I enjoy watching the gorillas at the Fort Worth zoo when the primate house is empty of visitors. Turns out they hate being stared at, they prefer side glances and low posture. So if I go kind of squat or stoop down by the glass in the building where the gorilla male can see the posture, I can see him kind of "sneaking" glances, intrigued that someone is doing it his way. They usually turn their backs on gawking visitors, don't bother to try to watch them.

I've also gone through there carrying a baby and had a mother chimp come hang out on the other side of the glass with her baby. You can't have the kid in a plastic carrier or in a buggy, you have to have them tucked up against your stomach or chest so the chimp recognizes a similar of mother and child profile. And they do respond.

SRS