I need help - my daycare child is hitting!

[MommyMommyMommy]

I take care of one little boy in my home. I've been taking care of him for about 3 months. He just turned one on Friday. His parents are divorced and he is mainly with his mom but his dad has him on Wednesdays and every other weekend.

This little boy hits ALL THE TIME!!! He hits my kids (5, 3, and 11 months) multiple times every day. He hits with toys which hurts! He even tries to hit me. He has hit my little guy on the head with a block while we were nursing!

I don't know what to do. I've told his mom and she knows but she said "When he does that, give his hand a little spank." I can't bring myself to hit a child while I tell him not to hit. I've tried just making eye contact and saying no. I've given attention to the kid that was hit instead of the hitter. I've tried the 'be soft' and shown him how to touch softly. I've removed him from playing and sat him in the other room. I'm sure there are a couple other things I've tried but don't remember 'cause this happens all day.

It's bad because it's always my kids getting hit so it brings out the mama lion in me!

HELP!!! Any advice would be appreciated!