Mantids are top predators in a food chain of other insects and even vertebrates such as small mammals, birds, or reptiles. Using large, compound eyes that are widely spaced for binocular vision, they swivel their heads as far as 180 degrees to spot prey. Most mantids are ambush predators, sitting still and waiting for prey to come close. Their long front legs are armed with rows of sharp spines that they use to grab and impale the prey. A few mantids actively chase prey, running after them on long legs. Once captured, prey are eaten alive, sliced and chewed up piece by piece. Wiggling prey may be eaten head-first . When at rest, mantids fold their long legs beneath them in a prayer-like position, or sit cleaning their legs with their mouths. Sometimes mantids eat each other (cannibalism), such as females that occasionally devour males during mating or hatchlings that cannibalize each other.

Insects are the only animals without backbones (invertebrates) that can fly. Wings of insects are flat and paper-thin, supported by a network of veins. They flap their wings at incredible rates, up to about two hundred times per second. Most insects have two sets of wings that work in tandem because they are coupled by a fold, a hook, or other structure that catches the back wing as the front wing beats. Wings are made of two layers of cuticle for strength. The front wing is often hardened to serve as a protective cover, leaving the back wing to provide most of the flying power. Many insects walk around instead of, or in addition to, flying. The good walkers tend to touch three legs to the ground at a time, alternating with other sets of three (tripedal gait). The stable triangles formed by the legs allows them to move quickly without falling over. Some insects "walk" on water or swim.