Yeah they are about 20 bucks but still I may not want to go that route. If there is some kind of inscent or something that I can burn in the cave, something that's not bad for humans, or something please let me know or give me some ideas on something else. I can hang a curtain up at the walk in door and for the 8x7 with the door up I was trying to see if there was maybe a curtain or something of some sort that I could put up, take up and down when needed or didnt need. I would want it to be able to flow air possibly, though there is a window and vent also above the door. Air would be able to escape pretty well as there are some draft areas on the cave also. I bought a 24 inch Max Air fan from home depot so that should circulate very well in there. Just trying to see how I can go about keeping out most of the flies and mosquitoes. Having those doors with something in front of them would keep a billion from just coming right in. I probably can still burn some kind of thing in there that will shy them away some????????