>>2031844A bug net.
Some are integrated, like in the pic. The net is sewn to one edge of the hammock and zippers to the opposite edge, along the entire length of the hammock. Mosquitoes can easily bite through nylon, but your protected underneath by an underquilt.
Other nets are completely separate from the hammock. They slip over the entire thing rather than attach with a zipper. These are usually after market, sold separate items that are pretty universal in how they attack. Most have doors that zip closed but a few have an elastic opening on the bottom. The zipper door style are ideal in conditions where you don’t need an underquilt (which probably doesn’t happen often in Canadia).