Scarlett Johansson knew she would be surrounded by wildlife while shooting We Bought a Zoo, but she didn't anticipate being intimidated by her non-human costars.

"I'm only scared of birds. Something about wings and beaks and the flapping. I'm terrified of them," the actress, 27, tells New York Magazine's Vulture. "If they'd asked me to put a bird on my shoulder I would've done it, but it would've been hard."

Birds aren't the only animals that make Johansson jump.

"I cannot stand cockroaches," she shudders. "That's one thing I absolutely couldn't do. But that's not really an animal, is it? It's an insect."

We Bought a Zoo -- which stars Matt Damon and Elle Fanning -- also features peacocks, which made Johansson uneasy. "I was terrified of them," she says. "Like, 'Ahh, don't get too close.' They're like, mean."

Johansson isn't averse to all animals, however. "Occasionally sitting on the couch with the dog, you're just like, 'Man, you're the best company. This is bliss.' Just the dog and a nice old movie and you're good to go."

We Bought a Zoo arrives in theaters December 23.