Most ant species, particularly the ones we are most exposed to, do not practice cannibalism - so no, they do not eat their dead like some others here have suggested.
Instead, similar to the way humans bury their dead away from towns, they dispose of them in small piles in specific locations. These may be either inside of their nest in a special chamber that is far enough from most other chambers so as not to contaminate the nest with a bacterial infection, or a location outside of the nest. Those outdoor collections of dead ants are called "midden piles". They are the dead ants and other "waste material" that have been removed from the main colony during nest maintenance. Ants keep a fairly clean house. They carry their waste matter outside of their nest and dispose of it, like mentioned earlier, in piles called "midden"s. As well as being a kind of dumpster, the midden also functions as a cemetery. Ants transport their dead there in order to protect themselves, their larvae and their queen from bacterial and fungal contamination. You may have also noticed that the more lone ants you step on and kill in your home, the more new ants will be moving in. That's because when an ant dies, its body releases a chemical called oleic acid. Oleic acid translates to "dumpster material" for ants. So even if you flushed those casualties down the toilet, the oleic acid had already been released; and other ants would still show up to respond to the initial call of distress to pick up their dead family members - the very ants you stepped on or flushed. Source(s): http://amos.indiana.edu/library/scripts/… Edgar
