When moving from place to place they go single file, but fan out when they get to feeding areas. Peccaries tend to feed early and seek shelter during the heat of the day, sometimes under logs or in burrows created by other animals. On BCI they often sleep lying on the forest soil in a sheltered location, or an entire group may squeeze into a large hollow in a big tree. Each group is made up of individuals who use scents from skin glands to mark each other for easy recognition. They rub against each other and all pile together when they are relaxing.
Peccaries eat fruits, seeds, berries, nuts, vines, snakes, and insects.
They locate underground bulbs and tubers by smell and root them up with their sturdy snouts. On BCI the flesh of various palm fruits and the seeds of Dipteryx make up an important part of the peccaries' diet. They have strong jaws which act like a vise and are used to squeeze hard seeds until they pop loudly. They eat the edible interiors and spit out the shells. Most non-carnivores have small canines but in peccaries these teeth are very large and sharp.