My parakeet regurgitated food to my other parakeet! HELP!?!?

I have 2 parakeets, and I just got 1 the other day ago....and I put them into 2 different cages like everyone said. Then I put them in the smae cage and when I put them in about 2 minuets later my one that i've had a long time regurgitated food!!!!! DID I DO SOMETHING WRONG?????? I THOUGHT ONLY PENGUINS DID THAT!!!!!!!!