From Nookipedia, the Animal Crossing wiki
Ants (アリ, Ari), in the Animal Crossing series, can be found at all times of day, throughout the entire year. They swarm over discarded turnips and candy, but not fruit, and can be easily caught. Despite there being a large group of Ants present on discarded food, only one can be caught at a time. Once one has been caught, the other Ants disappear. Ants sell for 80 Bells. The player makes a reference to a song named Ain't Misbehavin'. Ants can not be caught when the Beautiful Town Ordinance is active.
Donating to the Museum
In Animal Crossing
"I wonder, how do you think that ants manage to search out their food? Because the question really confounds me! I mean, really. Come now. If ants were our size, the area they traverse in their search for sustenance...would FAR exceed the entire size of our fair village. Can you imagine it, wot? Hiking that far for a snack? What is going on in their tiny little ant-minds, hm? Do they have some specific target in mind? Could it be they're just wandering about aimlessly? Hoo-rrrumph! Ridiculous and revolting!"
In Wild World
Once donated in Wild World, a trail of Ants can be found marching amongst the trees in the second room of the insect exhibit.
In City Folk
"Most people seem to regard ants as peaceful creatures, but the truth is that they're quite savage insects, wot? Indeed, when I was but a fledgling, I once sat on an ant nest by accident. The wretched things set upon me within moments. My poor tail feathers took forever to grow back.
In City Folk, Ants form a trail along the path on the central terrace of the insect exhibit. The Ants emerge from a hole in the wall and swarm over a pile of sugar that lies on the path some distance away.
In New Leaf
"Ants are small but very powerful and are able to carry items far heavier than they are. In the nest, there is a queen and also worker ants, making them somewhat similar to bees. In some habitats, ants actually make up between 15-20% of the areas total terrestrial-animal biomass."
Ants, from the family Formicidae, are insects that have existed for at least 110 million years. They are widespread throughout the world and are easily identified by their long antennae, large abdomen, and sectioned bodies. There are thought to be at least ten thousand species of ants world-wide.