With over 2000 species of mantids worldwide there is only one that is native to the west coast ... the California mantis (Stagmomantis californica). Mantids are ambush predators which means that they simply lie in wait for their prey food to come to them. And, what better place to wait than a milkweed patch that attracts many nectar-feeding insects during the daytime hours when the mantids are active. They feed upon beetles, leafhoppers, grasshoppers, flies, caterpillars, honeybees, each other, and just about anything they can catch that is smaller than they are... and they are successful hunters 85% of the time.
The spikes on the front arms stick to the prey so that it cannot get away. The praying mantids got their name because it appears as though they are praying when they rub their front legs together. Mantids are the ONLY insects that can look back over their "shoulder". By turning its head more than 180 degrees it can watch for prey in all directions and can see movement with its eyes (five of them... 2 compound and 3 simple) up to 60 feet away.
Mantids tend to be solitary critters as they "do not play well with others". Even though they are harmless to humans, the females of the species tends to decapitate the males after mating.
