Every day, millions of parents across the United States wake their children up, get them dressed and send them out the door to school with their lunches. And every day, about 30,000 kids come home in the afternoon with a few extra friends: head lice. While your first reaction to lice is to recoil, remember that lice do not transmit diseases like mosquitoes or ticks and are relatively harmless. Lice is common among children and does not represent bad hygiene. Because the transmission of head lice seems to increase during the wintertime, when children sometimes share headwear, here are some things you might need to know about lice as the temperature starts slowly dropping.