Aww, I love this idea <: Agents that are aware of night and day are something I've been becoming more interested in.
Code looks pretty good at first glance. To handle falling, you might use something like 'doif fall = 0' as a check.
I like the idea of them being super bouncy though; might help them wedge themselves into various places of the world, too. Maybe the bounciness could start off really high and then decrease as the egg ages, to give them more travel potential but still have a chance to eventually settle. Or maybe they'd be bouncy early in the day but slow down as night draws near. Whatever works :>
I'm interested to see how this progresses!