The next day we saw in the prairie a great herd of buffaloes. A halt was called and two old men harangued the young men . . . to show their skill in shooting down all the buffaloes that we saw. (Pierre Delliette, 1702)

Hunting expeditions generally were undertaken by individuals or small groups. However, in June most people left the villages for communal bison hunts in the prairies. Upon finding a herd, runners would surround the bison on foot. Then, firing their guns and arrows, the runners would drive the bison toward the remainder of the hunting party where they were shot. After skinning and butchering the animals, women and girls would preserve the meat by placing it on wooden drying racks and smoking it with small fires placed on the ground below. In 1688, Pierre Delliette, a French fur trader, accompanied the Illinois on a communal hunt that yielded more than 1,200 bison. Hunters also killed a variety of other animals on this trip, including bears, deer, elk, turkeys, bobcats, and mountain lions.

In the fall, when prairie grasses were dry and flammable, the Illinois used fire as a bison-hunting technique. Once they found a herd, hunters would partially encircle it with a large, C-shaped ring of fire. The hunters would then station themselves at the open end of the "C" and shoot the bison as they attempted to escape the flames.

The Illinois obtained fish from rivers and lakes using spears or bows and arrows. Nets evidently were not used for fishing because, according to one French missionary, other kinds of animals were so abundant that it was not necessary to go to the effort to make nets. The Illinois reportedly caught 25 different kinds of fish, including the eel, and a good fisherman could spear as many as 60 fish in a day.