2 years with aggresive(aggressive) behavior

I was pulled a side today at my daughters daycare and was informed that my 31 month old daughter has been bitting and hitting the other children and providers at the daycare center. I was unaware and surprise by this information. She has been at the same child care center since she's been 8 months old, and she has been behaving fine; until now. Two new providers have begun at the center a few months ago, and new children have also began there also.

I have noticed that around her cousins(about the same age); she is very aggresive (aggressive) and territory over toys or items that she wants. She is not an only child, however, my other child is 10 years old (so the 2 yr old is the baby of the house). She does have temper tranums and does hit/kick or pull hair with us at home(mom,dad, and sister); if she does not get her way. She is very smart, talkative (full sentences), and not fearful of others. I'm just unsure what to do with this behavior, timeout does not work; either does ignoring it. What can I do!!!!

[afekety]

I just finished reading a great book called "the Kazdin method for the defiant child" which was extremely helpful and got our 3 and 4.5 year old to go to bed and stay in bed within a week.  (not a 100%, but stuggling once in a blue moon is WAAAAY better than every. single. night.)

I know the examples are different, but I really think it's worth a shot.