Diet Drills feed on fruits, leaves, roots, seeds, nuts, fruit and invertebrates. Social organisation and behaviour Drills have two group types. One type is made up of 20 females who are led by a single, very large male. The other type is larger, and can include multiple males. During the dry season, many units may join to form troops with as many as 200 individuals.
Drills are active during the day.
They spend time in the trees, but most of their activity is carried out on the ground. After a gestation period of 174 days, females give birth to one infant. They are killed for their meat and for the damage they do to crops. In Nigeria, hunters use dogs to pursue drills. They are considered 'good game' as they stand their ground and several can be killed with shotguns before they will flee.