A bit late to the discussion, sorry. ThreeFeet has been offline a bit!
Get real! Going light does not have to mean “macho” going without nighttime protection. Scouts and parents in some locations will be concerned about Zika and West Nile which are mosquito-borne, as well as sandflies, black flies, and midges/no-see-ums. Yeah, mesh won’t keep out the rodents and plague and Hanta virus, but just don’t go where that is prevalent.
It’s not that hard to get some no-see-um mesh, seam tape, appropriate thread, and some parachute cord (to tie to ceiling and corners of tarp.) Teach ’em how to make the mesh inserts or get older scouts involved as a project, and/or bring in the parents.
Mesh inserts do help against mosquitoes, and also those awful stinging sandflies which inhabit many Southern US beaches and dunes. You can throw a cheap mylar space blanket on the inside of the mesh insert floor to limit damage to the mesh and help insulate against cold ground. All should have the multi-use mylar blankets in their daypacks anyway – as one of the 10+ essentials.
Also good to teach parents and kids how to use Permethrin on at least socks, outerwear, and mesh insert/tent screens, as well as Picaradin on exposed skin. Not a fan of Deet, as its retained in body fat over time, at higher concentrations it damages most synthetics, and some people are painfully allergic to it (think burning blistered areas on your skin, which can be relieved with lots of soap and water and waiting.)