yabu, its a pita, a big pita, we had a nightmare with ds3 who kept getting them i just combed and combed with conditioner and a nitty gritty comb and it does work but you ahve to do it pretty much daily for a good couple of weeks.
we just get a sign put up on the classroom door saying they have had cases of nits can you please check your child, i was up yesterday so checked last night! even when they are clear from nits you still need to check at least once a week to prevent an infestation [boak] and this thread is making me itch! i have eczema on my scalp anyway!
severe cases need to be reported, my dp works in child protection, they recenlty had a kid come to them who had open weeping sores on his head as the nits were that bad, took them ages to treat him and clear them they couldnt use chemicals as his head was so sore and they cut his hair very short but couldnt use clippers etc as again it was too sore to begin with, poor boy :(
but sending kids home wont help, those that care will treat them, those that dont wont and sending htem home wont change that.
i remember reading somehwere that any one time as many of 50% of kids at primary school would have nits if you checked them all, it is a part of primary school that gets better as they get older. it is a total pita tho, esp as i have 5 kids to wet comb with the nitty gritty and check weekly!