Adding to the Hitchcock element...
The birds like churros, too. I've told this story before, but a bird swooped down on my sister and her fresh churro and hit her so hard she had a mild concussion and had to go to first aid! I get so mad when I see people feed those things, I have to say something.
Now, if people are freaked out by birds, here's some interesting tidbits...
My first trip to DL in 2002, we were waiting for the fireworks (Believe...There's Magic in the Sky, fyi), a cockroach ran across our laps (ugh).
We were eating at the Hungry Bear restaurant at DL the same trip and there were stray cats (at least 7 or 8 of them) wandering through the seating area (a really large seating area, like Pecos Bill but out in the open).
Still same trip, in line for the monorail (which is inside Tomorrowland at DL), when a CM goes, "Look, there's Mickey Mouse," uh, sure, I looked down and there was a
real mouse running across the ground.
Guess that's what the cats are for.
So, mosquitoes and birds...nothin'. Check out DL to fuel your animal fears
Addenum: I've never seen any of the above animals since that trip to DL (I've been back twice and I'm heading back tomorrow), so please do not think it's a rodent-infested park. It's not at all. They're funny stories though.