Our theory is that it’s like Pac Man or Space Invaders – no point to it, not complicated, just kinda fun for no reason. Ben appears to understand that it’s not a “real” thing (it has no smell and he knows he can’t ever catch it) but he likes to chase it anyway.
Why do they like balls and such, when it comes down to it? Why do cats like toys with bells in them? I’m pretty sure they have no natural prey that goes “jingle jingle jingle”!
…Or… do they?.. Hmmn.