After Cornello had been eaten by Gluttony, the townspeople search for him but find a lot of dead birds. Envy arrives as Cornello and passes off a miracle and claims that the Cornello who had been "conning" everyone was sent by the devil while "he" was out of town. The miracle he performs is bringing the birds back to life, but out of everyone's view in the sky the birds explode.
Now I can understand how it's possible if alchemy was used, however, none the homunculi can use Alchemy except for Wrath, because:
His arm and leg belong to Ed, and as such can create an array with them since "the truth" was engraved into Ed's body and he had only lost one limb at that time.
So I am wondering, how did those birds come back to life?
EDIT: I'm referring to the original (first produced).