Lice Questions Girls are two to four times more frequently infested than boys. The sharing of comb, brushes, and hats, were found to be significant factors in head louse infestation. Children between 4 and 14 years old are the most frequently infested group. Lice are blood-feeders and bite the skin four to five times daily to feed. The louse bites through the skin and injects saliva which prevents blood from clotting; it then sucks blood into its digestive tract to live.