Golden lion tamarins are one species that are largely monogamous. Felipe Dana/AP hide caption

itoggle caption Felipe Dana/AP

The Asian tiger mosquito, an invasive, disease-carrying pest, was likely introduced to the United States from used tires shipped over from Asia. Jim Newman/University of Florida/IFAS/AP hide caption

itoggle caption Jim Newman/University of Florida/IFAS/AP

The beaked whale is one of the most vulnerable of all whale species to underwater noise pollution. Robin Baird/Cascadia Research hide caption

itoggle caption Robin Baird/Cascadia Research

The mosquitoes that feed on people are attracted to over 300 gases and other compounds emitted by human skin. CDC Public Health Image Library hide caption

itoggle caption CDC Public Health Image Library

Biologists normally look for the hellbender slamander, which is known by the nickname "snot otter," under rocks in streams. But now there's a gentler way: They can take water samples and look for traces of the animals' DNA. Robert J. Erwin/Science Source hide caption

itoggle caption Robert J. Erwin/Science Source

The Mount Charleston blue butterfly is a rare species found only in a few small areas high up in Nevada's Spring Mountains. Corey Kallstrom/USFWS hide caption

itoggle caption Corey Kallstrom/USFWS

Those are two whales coming up from the water, just feet away from two divers off the coast of central California. The image is from a video, which has gone viral, taken on Saturday. YouTube.com hide caption

itoggle caption YouTube.com