While many insects have become dormant as the cold weather settles in, head lice are now thriving—keeping nice and toasty warm on humans. Head lice are human parasites, spending their entire lives on human heads. Head lice are spread between people from head-to-head contact, or by sharing clothing or grooming items.
From kids piling their hats and coats together at school to those amusing moments when you try on all of the funny holiday hats at the store, head lice are getting many opportunities to travel and spread.
You are probably wondering now what these sneaky little critters look like. The human head louse adult is about the size of a sesame seed and grayish-white to tan in color. Head lice eggs, called nits, look like tiny yellow dots and are often mistaken for dandruff, though you cannot brush them off. Adult lice lay nits on hair shafts close to the scalp.
Once the nits hatch, the lice will feed on very small amounts of blood drawn from the scalp. Their bites can cause intense itching and small patches of inflammation. Head lice do not transmit disease, but heavy infestations can cause severe scalp irritation. Also, persistent scratching by an infested person can lead to secondary infections.
Nits need to be removed mechanically, using a special comb. Lice cannot survive off their human host for longer than 48 hours, and therefore, do NOT live in the environment! This means that there is no reason to apply pesticides to a home or business in response to a head lice outbreak. Also, head lice are host specific, meaning they prefer to stay on humans, so there is no need to worry about treating the family pet or that the pet can spread head lice.