Typically found in the warmer areas of the Americas, Leafcutter ants feed on a special fungus that only grows underneath the nests that they build. In order to cultivate their fungus, and keep it free from molds, the Leafcutter ants feed it with contant freshly-cut plants (hence, the name). However those plant leaves have a little spice added to them first. The ants will add a little saliva and also a little rectal fluid before putting it on the compost pile.
If the ants encounter a plant that is toxic to either the fungus that feeds them, the can detect that through chemical signals, and then will discontinue cutting and add that particular plant in the future.
This fungus that is created from a mixture of the ants’ fluid and freshly cut plants hasn’t been seen anywhere else on Earth except for in the Leafcutters’ nests.
Leafcutter ants build humongous nests that can go deep into the ground up to 26 feet. These nests can have up to 8 million Leafcutter ants in just one colony. These nests are often referred to as cities because they are so huge.