"jump"

I hold Aaron up to my stomach and say "jump" and he kicks his feet. At which point I lift him into the air as if jumped himself. I've also noticed he seeks attention now. Only 3 weeks old and he cries because he wants someone to play w/him. Unlike 1 week ago where food and pacifier were the only things that would stop him from crying. I suppose he's teaching me new words too, where everything is a homonym. cry=pacifier or food or play w/me or just because I can or...