Saben doesn't just like keys, he is obsessed with them. He could easily spend an hour putting keys into keyholes. I need to find some way to channel that energy with a toy that I don't have to keep an eye on all the time. But I think if it was a plastic dohicky going into a plastic hole, he wouldn't find it quite as exciting. Any ideas? I thought of padlocks, but our floors dent easily so I don't want him running around with a heavy padlock to drop on the floor.