Some of the best protection I have used in the deep backwoods is Cutters brand liquid. I also use generic liquid purchased at Military surplus stores, only because it contains higher amounts of DEET. It may not be appropriate for children, and you have to be careful, it will fog certain plastic lenses(what does that tell you?).
In windless conditions, the burning mosquito coils placed strategically will work well. I use citronella, but it is only marginally effective.
Tarp