Originally Posted by EntropyControlSpecialist:
The magical, nice daycare lady has spoken and it is so. 
Parents of aggressive chilren rarely take "criticism" of their aggressive child well and seem to want to pinpoint the blame ANYWHERE else but their own lack of parenting. So, be prepared and don't let that surprise you if they start wanting to know what has changed at YOUR program since you're just now addressing the issue in a big way or how are YOU correcting it because they "don't see this at home." 
This!
I am always amazed when parents say they "don't see this at home." Especially when it's an only child. Yes, you don't see this at home because there isn't another child at home to bite, hit, kick, smack, steal toys, push over.