S.M.
I don't know if you can do much if it's only happening at daycare, but as a former worker in a day care, this worked for us with a hitter...1st, teach your son "gentle" or "soft" or whatever word you want to use to associate being nice to someone. Then, stroke your cheeck with his hand and say "gentle" if he hits or pinches at home, do the same thing, grab his hand and stroke your arm and say "gentle". My 14 month old has already learned this, so a 2 year old should have no problems. The second thing would be to tell the daycare workers to make sure they are using a stern voice when they say for him to stop. We tended to say "no no, no hitting" in a sweet voice, and that just didn't cut it. We had to in a stern voice say "no hitting" and remove him immediately to a "time out" place...only for 2 minutes if he's 2, but we did have to remove him so he learned. If they start with the "gentle" approach and that doesn't work, then add the time outs.