My name is Tim Mhlmann and I'm a junior researcher here at Wageningen University
and I am researching mosquitoes and biting midges.
But in my free time, I am a passionate ant keeper and I have around 20 different species at home.
Some of which I have brought colonies of for you to look at after the talks.
So first I will give a talk of around 25 minutes, about the diversity of ants and how we can benefit from them
and then after me Jitte Groothuis will take over
and he will talk about the brains of ants.
So let's have a look at the diversity of ants.
Here you see some pictures of seven different ant species
and on top you see that there are huge differences between their jaws, their mandibles.
They are formed in strange ways and often for a specific function.
On the right side you see the Honeypot ants
which have jaws formed in such a way that they can store a lot of food.
So when there's not a lot of food available, they can still feed the colony.
And on the bottom you see three species.
You see they have similar colours
but you see that within each picture, so within each species,
there's also a lot of diversity.
For the leafcut ants, you see small, minor workers
but also very large, major workers.
And for the trunk ants you see workers with flattened heads
and also more or less normal workers, as we know ants.
For the big headed ants, well the name already says it,
you find ants with very big heads.
Their heads are full with muscles, so they can power the jaws
and they can bite very fiercely.
So how can it be that they have become so diverse?
That there are so many species of ants?
Well, first of all, they have occupied almost the whole earth
so you'll find them almost everywhere.
Secondly, it may be because they're already on the earth for such a long time.
This is a picture of a fossil, and it is estimated to be around
one hundred million years old.
So ants were actually already living on the earth
when there were already also dinosaurs
and we only came around about 150,000 years ago.
So the ants have a hundred million year head start
when it comes to living in social societies if you compare them to us.
And also in numbers, the ants easily outcompete us.
So you'll find many, many more ants on the planet than you'll find humans.
Even if we look at the total weight
of all the ants combined, it is estimated that
they outweigh us four to one.
So you'll find four times more ants in weight than humans.
To understand how they could become so successful,
you first have to understand how an ant colony is built up.
It all starts with a queen ant,
and the queen ant lays her eggs.
From these eggs, larvae emerge,
and the larvae are the growing stage of the ant, so you'll find
small larvae, medium sized larvae and large larvae.
This is why ants collect so many insects outside,
to feed it to their larvae.
When the larvae are fully grown, they will pupate
and some will spin a cocoon around it and from the cocoon
the ants will emerge and from then on the ants don't
really grow anymore. Maybe their brains
change and Jitte can tell you more about that in the next talk.
So, either worker ants or soldier ants,
as we have seen in the previous picture,
will emerge and sometimes,
most of the time that is once every year,
winged individuals will also emerge from the cocoon.
Those are virgin queens, new queens,
that can found a new colony.
Also you'll find some smaller ants that have wings,
and they are the the males that will fertilize the Queen.
So, let's have a look inside of one of the colonies and this
is one that I also brought tonight.
It's here on the table, but it's just for you to see what it looks like.
Here you see a worker walking around
with a bunch of eggs. You also see the larvae lying here with the black inside
which is the food inside their gut. You see the
big cocoons, that's where the new worker ants will emerge
and you see the normal workers, but also the soldier ants with the large heads full of muscles.
Like I said, you'll have time to look at this in more detail later on
because they're here on the table.
When the colony is large enough and old enough,
queens will emerge.
You probably all know this phenomenon, when you never thought you had any ants
in your garden and suddenly they're everywhere, even inside your
house where you've never seen them before.
Well, these are all queen ants that are
flying out, chased by males that also
have wings, going on their mating flight.
And these queens are full of proteins,
the back of the Queen is full of protein,
full of nutrients to found a new colony.
So when they have mated in the air, the male will die
as he has no other function than fertilizing the Queen,
and the Queen will drop to the ground, will throw off ther wings,
and she will start a new colony.
She finds a suitable place, lays some eggs,
and nurtures them until they are workers
and from that point onward the Queen is an egg-laying machine.
And she can actually live up to 20, 25 years
using the sperm from that one male.
So from this point onward, the colony can grow exponentially. If they
find enough food and they have a good territory
you'll find thousands or even millions of ants
and they can build huge structures.
As you can see here, many of you probably know this structure from the forest,
it's the Red Wood ants that make this,
here you see them in more detail.
They gather a lot of sticks and needles from the woods to build their nest.
But what you see outside, is also more or less the same size underground.
So, it's a huge colony, a huge nest that they build,
in which you can imagine there are thousands or even millions of workers inside.
This is in the more temperate regions where you
find this kind of species but of course
also in tropical zones you will find
ants that can build large nests and
that's what we're going to see in the next movie.
Here, you see a nest of leaf-cutter ants.
They're considered a pest species in South and Middle America
because they attack the crop of farmers.
So, scientists wanted to know how big a nest of this species can be, and they
so they started with some buckets of concrete to fill the nest, but quickly they realized that
it was not enough. So, they had to get a
truck and a second truck and a third truck
until finally they had enough concrete to fill this nest.
You can see them digging here. They had to use machines
to dig it out.
And, it's actually a miniature city of ants,
it was filled with millions of ants that constructed this.
So, it's amazing how they can transport all this soil
even though they are so small.
So like I told you, those are the leafcutter ants,
and we see them here as well,
and what do they do?
They collect leaves. That's also why they're considered a pest insect,
because they attacked the crops of
farmers and you can see them running
around here in lines with the leaves,
bringing the leaves back into the nest.
And why do they do this?
Well, these ants have developed agriculture.
They know how to cultivate crops so they're
not eating the leaves themselves but
they're chewing the leaves into pulp and
they grow a fungus on this pulp and this
fungus grows all over the leaves and
then it forms small buds, nodules which are
full of protein and the ants will eat that and
they will feed that to their larvae.
So, that is why they are collecting so many
leaves, because they cultivate a crop.
What else can ants do,
what also we humans have developed?
Well they also store their food.
They store grains. So just as we harvest
our grains, the harvester ants will also
collect seeds outside and keep it for
times when they have need for food.
Here you see the entrance of a nest of
a harvester ant and outside you see
all the remains of seeds that they had
collected and already consumed.
Here you see one of these ants carrying a
seed. So they go out in the surroundings
collecting all these seeds, and store them for
when they need the food.
In this ant species, you also see the differences within
the species. We have the smaller workers
that collect all the seeds and you have
the bigger ants, the soldiers, they have large
heads so they can defend the colony but
it's also important because they have to
crush the seeds. The seeds are very
strong and they have the large muscles
and the jaws to actually open the seeds
to get to the food.
Besides keeping crops and storing their grains,
they also keep livestock.
Not livestock as we know it of course, but they keep Aphids.
Aphids, 'Bladluis' in Dutch,
secrete a nice sweet fluid and
you'll see it in the movie that I have here.
When an ant touches the back of this
aphid, a nice droplet of sweet fluid will
be released by the aphid and ants really
like that so they come back all the time
to harvest this sweet treat that they get from the aphid.
And what does the aphid get in return?
It gets protection.
Like we take care of our livestock, the ants also do that.
This is a predator of the aphid, you see it eating one of the
aphids here. It's a lady beetle.
But when these aphids are protected by the ants, you see that they chase it away.
They won't let it hunt their livestock and
actually some of these ants even take it
a step further and they take down some
of these aphids down in their nest
when it's becoming winter and too cold
outside for the aphids to survive.
They put them on the roots of plants so that
they are protected during the cold
weather outside and when the weather is
better again in spring they take them up
put them on the plants so they have a
new start with their livestock.
It's really nice how they have developed this.
So they defend their livestock against enemies
but also have to defend themselves.
Here you see one of the ways that they can do
it with formic acid. The Red Wood ants
that we've seen before spray
formic acid which is not very nice when
it touches you, or if you get it in the eye
you won't really like it and a lot of enemies
of the ants also don't like it.
Some ants have taken this even into an even more extreme
chemical warfare and they can have
a mixture of chemicals in the body and
then they explode.
The substance that comes out of them
is very sticky and all the ants
that surround them, all their enemies,
will get stuck in this sticky substance.
So the ant has to die, it has to sacrifice herself
but in the end she will kill a lot of enemies.
What else can be used to defend?
Well, we already discussed the soldiers which
have large heads, that are full of
muscles and have strong jaws so they can defend the colony.
And some ants have a sting like a bee or wasp. They can sting you
and actually the most painful insect
sting is produced by an ant, it's called
the bullet ant. You can look it up on
youtube, where there's some incredible movies
about this and it actually feels like
you've been hit by a bullet.
So these are four strategies how they
can defend themselves.
Some ants have actually taken this to an
extreme and they are called army ants.
You see a trail here of army ants. I've seen
this in Western Africa and these
ants are always on the move. They don't
make a permanent nest, but they're always
looking for new hunting ground, for
new sources of food. If you zoom in
on this trail you see the workers
running around and lot of soldiers with
big jaws protecting the colony but also
looking for new food sources.
And this is in Africa but you also see something
like that in South America,
Central America where it's even more extreme maybe.
The jaws are huge
and you can imagine that it can easily
pierce through your skin. Yes, it actually
can and some local tribes make use of
this. If they get a cut,
so they are cut by something, they go and
search for these ants, they grab a soldier,
let it bite on the two sides of the wound and
then remove the back of the ant.
The head will sting, the jaws will stay
closed and they put a nice line of
several of the soldiers next to the wound
and you have a very nice stitch.
So a great way to use these ants
when you are surviving in the jungle.
Besides these army ants we have other
ants that have developed strange jaws and those
are the slave making ants. These ants can
actually not take care of themselves,
they can not really feed themselves,
can not dig very well, can not take care
of their brood, so what can they do?
They can hunt.
They can hunt for pupae of other ant species.
So they go out to a different ant species nest.
they run in the nest and just overrun the other colony,
they take the pupae, the cocoons out, and
bring it back to their own nest and when they
emerge they think that they're at home.
They feel perfectly fine and they start working,
start taking care of their slave makers,
they start taking care of the brood and
you'll see two species of ants seemingly
in harmony living in the same nest.
Although, the left one is actually a
slave of the right one.
Jitte will go into more detail of how this works in the
brains of these ants.
Fighting is not the only way to defend yourself.
What else can you do?
Well you see it in the next picture.
This strange looking ant has a strange head. But why is it like this?
You see it quickly in the next picture;
it lives together with trees
and it makes its nest in trees.
The head of the ant perfectly fits in
entrance of their nests. So only those
ants that know the secret password may enter.
These are not the only ants that have interactions with plants,
you also see it in these plants, the acacia trees.
You see that the bottom beneath these
trees is completely empty. It's also called
the death zone because there's no other plants
even though it's in the middle of the
tropical forest so it's really strange.
And this is because there are ants living in
these plants and I actually brought the thorns
that they make. These thorns are hollow.
You see a picture of it here
as well and there's a little hole inside.
So, the ants make their nest in these
thorns and that's not the only structure
that the plants make to attract these
ants. They also make nodules.
They're full of protein, full of nutrients and ants
will collect these and can use them as food source.
So everything they need is present in
this plant. So they don't have to
leave the plant; why would they leave the plants?
Well they only do that to protect their
home. So if there's other plants in the
surrounding of their host plant trying
to grow, they will go out and sting it, bite it,
just as long until it dies, so that their
home, their nest, can grow out into a big large tree.
Not in all interactions with plants, have the plants actually adapted, but the
ants can adapt the plant as well.
So in this case, this is the weaver ant and they use the silk
of their larvae to weave together leaves
of the plants and of the trees in this case.
So they nest inside the tree and
they can have several of these nests
throughout the tree, even in different
trees. And they see the trees as their
home and as their hunting grounds.
So that's also what they will do. They will
collect a variety of insects in these
trees. Other ant species but also
caterpillars or crickets. Harmful
insects that would normally harm the
tree or the fruits that are growing in there.
And farmers make use of that in
Africa and South America. They promote
these ants in the tree and they even put
up lines between the trees and 'highways'
so that they can easily transport
between the trees so they can kill
the pest insects for them and they get
the rewards: nice juicy mangoes in this case
that are protected by the ants.
This is one way how we can benefit from ants.
How else can we benefit from ants?
We asked the students of Wageningen University
through a WUR app about
what they thought. How do you think we
can benefit from ants?
These are some of their replies. So you see that many of
them said: 'well, we can work together,
be more social and co-operate like ants.'
Definitely we can learn a lot about that. We have to say
that they had a hundred million year head start.
So I can imagine it is a bit harder for us.
''They're soil engineers. They provide nutrients and oxygen''
And indeed you've seen how they build huge nests and how they put oxygen
inside the earth.
''They're an important part of the food chain and clean the environment.''
That's definitely true.
Some say, they can be used for human consumption or
biological control. Like I just told you,
can indeed be used as biological control.
Some even said ''they can stitch wounds'' so the story
that I told you was already familiar for some of you.
So, I want to go back to human consumption, because indeed
ants can be used as human consumption and
they are already used for human
consumption in Central and South America.
The leaf cutter ants, the queens of these ants, are collected when they are flying out.
Like I said, they're full of nutrients, full of proteins so
they are a very nice snack.
Also the weaver ants, that we have
just discussed, they're eaten
in asian countries and they're sold for good
prices on the market there.
Also in Australia, the aboriginals already knew
that if you find a nest of ants
from the honey pot ant, you have to
start digging to find a nice snack.
So if you want to know more about edible
insects you can come to a lecture of
insects and society which will be on the
22nd of February and there they will
talk all about edible insects.
So then there is one more thing, that we can
benefit from ants and that's how they navigate.
A lot of our navigation systems originate
from how ants find their way.
There's different ways in which they can do that,
they use their vision, they can even
count their steps. You see that in
middle picture, where scientists manipulated
the legs of these ants. They either
put stilts underneath their legs
or they cut the legs into little stumps.
Only those who had normal legs
could find their back the way to home.
Actually the ones with stilts
underneath their legs would run
further than their nest and the ones with
the stumps they would stop earlier than
their nest. Finally, they also use
odour so they can attract
each other with the use of chemicals.
We already know a lot about this
but also a lot we still don't
understand but we can definitely use it.
And as one student said in the
interview: ''Ants can walk backward to their home
in the middle of the night.''
If only we could do that. Right?
That would be amazing.
Well, I don't think we can learn that
from them but we can definitely learn a lot
from them. So tonight we have seen
a lot of the diversity of ants. I've
discussed with you how they defend
themselves, how they cultivated crops,
how they keep livestock, how they have
interaction with different plants and
how we can use them in biological
control, as a food source but also for
our navigation systems.