Kaitlyn started doing the same thing about a month ago .I spoke to daycare and they said that all the kids there are doing the same thing so I think they also tend to pick it up from there. We just kept explaining to her that when she hit us she hurt us and we would act (really overact!) about how it had hurt when she hit us . And now that I think about it she has not done if for about a week ..but it took a couple of weeks of persistance.