Mimicry (looking like something else) is a great form of protection. If you are very yummy, you want to look like something that is very distasteful and live nearby. Ants are well-known for their aggressive behaviour and all the nasty chemicals that they produce. So it’s not surprising that many other invertebrates (spiders, beetles, caterpillars) mimic them, to gain protection from being eaten!
Ants mimicking ants in SE Asian rainforest
But ants mimicking another species of ants – unheard of. Well, not entirely unheard of but it’s highly unusual. Every ant species have very effective anti-predator (either through chemical weaponry or sheer mass aggressiveness or painful stings or combination of all three). They are more famous for being the model (that is other organisms mimic them) than being the mimic.
One species of ant Crematogaster inflata have prominent and bright yellow anti-predator gland, so effective that another ant (Camponotus spp.) ‘decided’ to take advantage of the distastefulness of the chemical produced to look like them. When the researcher first discovered this in 2004, they couldn’t believe their eyes. They need prove to convince themselves and others that this is indeed an example (the very 1st in the world) of ants mimicking ants.
Can baby chicken learn the distastefulness of C. inflata?
The researcher knew that they need to find a visual predator (because of the yellow warning colour) that are naive (i.e. never encounter the mimic or the model before). And the best they could come out is newly hatched chicks. First, they fed the chicks with the supposedly yummy Camponotus spp., and indeed the chicks happily peck up the ants.
Next, they present the naive chicks with the supposedly unpalatable model Crematogaster inflata and for after 2 or 3 tries of trying to consume the ants, they quickly spit them out and eventually avoid them completely. So now the researchers are getting excited, but they still have to prove that the chicks (after learning how distasteful the yellow ants are, they will avoid the other yellow ants)!
Is the colour itself enough warning?
The researcher lastly presents the palatable Camponotus spp. to the chicks that have the bad experience of ingesting C. inflata and lol and behold, the chicks avoid the Camponotus spp. ants, even though they are palatable. That’s the proof that the researcher was looking for. The first confirmed case of ants mimicking another ant species!
Source: Fuminori I, Hashim R, Yek SH, Kaufmann E, Akino T, Billen J (2004) Spectacular batesian mimicry in ants. Naturwissenschaften 91: 481-484.