hmm, that's interesting....mojo likes to sleep on my breastbone or above my head on the pillow when i'm lying flat. squirty and magic (mojos son), who rarely sleep on me, but do on occasion, sleep on my bladder (squirty is 7#, magic is 13#). RB cats TJ and Fish liked the breastbone, Janice and Isis(TJs daughters) were a behind the humans knee sleepers....and i do not recall which nipple they used. magic liked the upper chest area on mojo as i recall. thanks for the interesting idea, and i'm sure when i'm at the party at wayne&stephanies house(major cat lovers) tonight, i'll use this question as a conversation point......;