We have an 11 yr old, neutered miniature schnauzer. He's a big baby and
loves everyone... except kids. For some reason he transforms from a
lovable furball into an aggressive, biting "mean dog" in the presence of
kids under about the age of 12. We cannot account for it. It's
embarrassing and even more than a little worrisome. For the longest time,
I thought he was just wanting to play with them like he does with anyone
else he sees. But he really does want to bite them, and has in fact nipped
at the daughter of a friend of ours who knows to dog well.

What is it about kids that has this effect on him that adults do not?
And what can we do about it?

BTW: He's already on amyltriptoline (probably spelled wrong) for
"separation anxiety", so we'd rather not medicate him more than necessary.