The area we go to most is a designated camping spot just outside the gate of Joshua Tree National Park on BLM land. The Pinyon Pines area is a good anting area, and I think there are some camp grounds around there. Also, Box Canyon near Mecca, CA is an awesome camping spot, but probably not a place you want to be during the monsoon thunderstorms. I got stuck in a flash flood there. The road washes away every summer.
I can confirm to everything here besides the monsoon experience. I camped at Painted Canyon in the same canyonlands near Mecca recently. There's plenty of Veromessor pergandei, Myrmecocystus sp., Pheidole sp., and other ants out there.