They attach themselves to the hair shaft and take about a week to hatch. The eggs remain after hatching and many nits are empty egg cases. Nymphs hatch from the nits. The baby lice look like the adults, but are smaller. They take about 7 days to mature to adults and feed on blood to survive.
Adults are about the size of a sesame seed.
They have six legs and are tan to greyish-white. The legs have hook-like claws to hold onto the hair with. Adults can live up to 30 days and feed on blood. Head lice cannot jump, hop or swim. Anyone can catch head lice, but preschool children, primary school children and their families are most at risk.