I am a new provider and I have had an 18 month old in my care for the past three months. She had difficulty adjusting, but after the first 6 weeks, she has been great. I added two more kids at one month intervals who are doing well (plus I have my own two). Last week the 18 month old starting behaving very agressively to my 10 month old; every time she sees her she squeals "noooooo" and either kicks or tries to hit her (on Friday she actually slapped her in the face for no reason). I gave her a time-out, although I am not sure if that is effective at this age. This week I have taken a new tactic and I am giving her zero attention for it, just physically stopping her whithout making eye contact or talking because I have been thinking that she is doing it to get attention since we had a new child start last week. She is still doing it, but I am going to continue for the rest of the week like this and see if it improves. Any suggestions on how to deal with this type of behaviour would be appreciated!