I am not sure it is wise to treat the children with Frontline, no matter how bad their fleas are.....oh, you mean touching the DOG after it is treated?? Oh, just follow the directions, as others have stated, and don't let your kids lick the dog for a few days! We have used it for years and our kids don't appear to be glowing green or licking themselves in weird places or anything! OTH, they ARE preteen and teen now- maybe the Frontline caused the moodiness, talking back and avoiding their chores!