I'm planning to do a couple of backpacking trips in southeastern Utah this fall (Dark Canyon, Grand Gulch). It'll be my first experience sleeping in canyons, so I wanted to see if I could get some advice on the right gear to use for sleeping.
My initial plan was to use a BPL Vapr bivy, light sleeping bag, GG polycryo/NiteLite below, and a cuben fiber or sil-nylon tarp draped above (maybe staked/tied off against wind). After reading more about the bugs, mice, and other creatures that come out at night, though, I started to question if I needed to go with a tent so I could stow everything away and avoid having bugs between my layers and in my gear.
Any advice about sleeping with the creepy-crawlies in the desert?

