I agree with Chaci... maybe try having the kids give him a treat, might help. I have a soon to be 7 yr old daughter and though I know Meka loves her, but sometimes when they were younger, Meka would nip at her or growl a little if she went to pet her. When she did that, I would tell her "no" and to "play nice"... and she's much better now. We no longer have that problem. I think its really important to stop or rather correct the problem when it occurs. And to also be consistant with the method of correction. I had also read that its a dominance thing, when it comes to kids and little dogs. Hope this helps
