Answer:
the chimpanzees become habituated to your presence
Explanation:
Habituation is condition in which an organism sensory system, and the CNS, after a period of time stop responding to a particular exposed stimulus.It occurs at different levels of the nervous system.
In most cases sensory impulses are sent to the brain.But the brain did not process the information.Rather during habituation the brain filterers the incoming sensory information flowing into it from the environments, to remove the less important stimuli while focusing on most important ones.It is when these new pathways developed that the Chimpanzees will get used to the intern.
It also occur in human when we get jaded with a particular odor after continuous exposure.
Animals investigators always rely on habituation to get best results from the study concerning the animal.