Well, me and all my friends are in college, all of us about 20-21 years old, and AC is one of their favorite bands right now. We've all been into experimental/shoegaze for a long time. I mean, who else is going to like Animal Collective? What kind of demographic do you think they fit into?
Also, what I found funny - I'm sure a majority of the fans there have only heard MPP. How can I tell? No one went crazy for them opening with Chocolate Girl (which was fucking fantastic).
But seriously though, AC fans kinda ruined the show. There was a ton of pushing and even some moshing too, which kinda surprised me given AC's music. I mean, dance all you want to, but for a band like AC, I'd rather not deal with getting someone thrown into me every other song. Combined with their terrible behavior during Grouper (at one point I asked the people behind me to please whisper because I was trying to take it in - she said ok... and then kept talking at a regular volume), AC fans managed to piss me off more than Radiohead fans.