My ball python just seems agitated (tries to hide in the nearest crevice) when I take her out on acid, though to be honest she's always kinda hit and miss with her mood except around my girlfriend (she and my snake seem best buddies, but it's okay cause I'm cooler with her cornsnake than she is

). If I catch her when she's asleep in the afternoon she's usually pretty mellow and groggy seeming hahah, and then I can hand her off to people.
My guinea pig is inherently mistrusting and usually acts kinda odd when I'm tripping, which is odd since he'll be totally chill with a bunch of drunk girls shouting about how cute he is in his face kinda thing. Guess he's cool with the ladies, but not the hippies hahah!
Then there's my dog, who is also just very strange, but she and I seem to bond well when I trip these days. We have play fights and run around the yard together.
When it comes down to it, drugs alter our perceptions of many things, and thus I think it's safe to assume that our pets are not in fact acting much different than usual, but rather we are perceiving them to do so.
Of course it could also be like others have said, that when you're having odd vibes while tripping, your pets pick up on this and act accordingly. Who knows!