The Collaborative International Dictionary of English v.0.48:

Pip \Pip\, v. i. [imp. & p. p. Pipped; p. pr. & vb. n.
   Pipping.] [See Peep.]
   To cry or chirp, as a chicken; to peep.
   [1913 Webster]

         To hear the chick pip and cry in the egg. --Boyle.
   [1913 Webster]