The preying mantis is an excellent hunter. Does it have depth perception to help it snag insects? It turns out that it does. Scientists put tiny 3D glasses on them and showed them 2D and 3D videos of insects, and they only went for the 3D ones.
The mantis (and we) use eyes that are separated to get binocular vision to get two slightly different perspectives on things. Various cues from the two images and how the eyes line up give us information on how far away things are.