They're fun to have around, they unlock doors. I dunno, don't ask me, maybe they have a monkey wrench xD. Anyways they are good to have on your shoulder on neutral as they throw poop at enemies when you are hit, which slows them down. Good for taming things like trikes, just keep whistling neutral, passive so they don't absolutely hammer the thing your trying to tame
These dudes are quite useful. But even more useful in multiplayer. If you manage to get them inside a base they can unlock doors during raids. And they can throw poop! You can also equip them with hats which looks better on them than hoomans.