9/25/2010

What about nits (eggs) not right near the scalp?

Nice picture, huh? I like and encourage the reading of a variety of head lice fact sheets from a variety of research centres/universities. While the facts are usually (but not always) the same, they occasionally use different language that helps you understand an issue more clearly.

For example, here's an excerpt from the fact sheet from the Entomology Department of the College of Agricultural Sciences of Penn State University. It is regarding the viability of eggs that are not right near the scalp:

"Eggs hatch in five to ten days when the temperature is between 95 degrees and 100 degrees F (35-37.8 degrees Celsius). Below 74 degrees F (23.3 Celsius), most eggs will not hatch. People finding nits on hairs wonder if they are old nits which have already hatched or new nits which may still hatch. Since human hair grows about 1/2 inch per month, any nits found on a hair 1/4 of an inch from the scalp would be approximately 16-days old, and would have hatched already, or will not hatch."

So, you probably don't have to worry about those far-way eggs because they were laid a long time ago and if they haven't hatched yet, they are not going to. Or, what you are seeing could just be the egg casing. Still, I like to remove them to avoid confusion.

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