Although they become extremely shy and cautious where persecuted, vervets quickly become very tame and bold where their presence is indulged. It is never wise to feed them near a dwelling, as once they realise food is available they will soon attempt to enter the house itself, and then can become a great nuisance. They are, however, exceedingly nervous, highly strung and excitable by nature and though, in the wild state, generally of a gentle disposition and capable of great affection when in captivity, cannot endure teasing of any kind. They will follow a prowling leopard, barking and coughing at it incessantly from the trees - so betraying its movements, as do baboons. The leopard no doubt catches many monkeys as they roost huddled together in the crowns of large trees.
Vervets are active agents in the forest seed dispersal.
As they sit in the branches eating fruits a constant patter of falling fruits, seeds and droppings flow to the ground below, the droppings being filled with seeds or pips. The young are born at any time, but principally during the summer months of December and January, when infants appear almost daily. One young per birth as a rule, occasionally twins have been recorded.