Like, they sense that some shit is going down because of the UFO sightings and whatnot? That could work. Maybe his presence there somehow upsets them and him leaving calms it down, so he just decides that until he figures out what's wrong, it's better if he leaves. Yeah, that could work. Since there aren't likely to be any animals on campus, he probably figures it's best to just stay there til the end of the day rather than going back to his friend's place now to deal with a possibly hostile Baxter.