I have never really seen them in my snake cages. But I have in lizard cages, and at times i would see them on the lizards eyes. I presume for moisture. Pester might be to strong a word, maybe annoy?
But I would like to hear more about the benefit? I enjoy new information, and if there is a health benefit that's pretty cool in itself.
Also as far as a pest, part of my experience is from helping others as for a short time I helped a friend at his pet shop. In most cases you can not make things to complicated. People saw BUGS and freaked lol. So, some easy and safe means that were at hand were explained to kill the bugs. There my game plan was KISS! 
Serious what benefit. I want to male one large cage for a few lizards to be named later. I even want to try to setup regions ideal for egg laying to see if the lizards lay in the proper spot and they hatch.
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Thanks for reading.
Tom
www.HerpZillA.com
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