[John Brinegar]

Yes, but if there were no way to cleanse a gate of lice, one would still expect to see a slow but inexorable spread of infestation. That's all I meant by saying that something must do the trick. I also wonder how a gate would be infested with thousands of lice when it seems that reproduction requires the eggs to go through a gate. To build up a huge population in one gate, it seems that the lice would have to be breeding inside it.

I think maybe I need to stop thinking about this so much...