How do I know this there are many reasons:
1. Lovingly walking around the house chewing on a Croc or two
2. Making sure he has a matching pair and putting them on his hands
3. Throwing them all outside when Daddy's not looking
4. Carrying them to unknown parts of the house to watch the adults go looking for them
5. Bringing the correct person their shoes - a suttle hint he wants you to go outside with him
6. Mom getting to work this morning and noticing teeth marks on her sandles
At least it's not the usual twigs, dirt, leaves, or crumbs from his meal off the floor - see it could be worse.