How can i respond when people make rude comments about my family/kids?

i have 16 kids (some are mine, some adopted) with 2 on the way. they are all beautiful and for the most part well-bahaved (if you want to know the family story see my previous ques.)when we go out somewhere it's the same thing "ever heard of birth control", "are you mormon". a whole bunch a rude and nasty comments. i always try to ignore them, but it sometimes it hurts the younger ones feelings (especially the adopted ones) when people say that. once my 7 year old tried to run away because some man said "i highly doubt you want all those kids, you were just too lazy to use a condem". how can i stop this. the older ones just turn their heads and walk on. but it's still hurtfull.