2 under 2 losing my mind!!

Ne

I have a two year old boy and an 11 month baby girl. Baby girl is a sweet heart and so is boy but my toddler hits her a lot like out of no where and for everything. Bites her punches her pushes her. Steps on her everything. Tell me this is going to end soon!!!! That he doesn’t hate and it’s just a phase!!! Please mommas help me!!!