crawling images - Joel Sartore

Red-bellied piranhas surround guests crawling through an underwater tunnel at the Houston Zoo.

A Hoffmann’s two-toed sloth (Choloepus hoffmanni florenciae) at the Gladys Porter Zoo in Brownsville, Texas.

A Stock Island tree snail (Orthalicus reses reses), a federally-threatened species.

A federally threatened Stock Island tree snail (Orthalicus reses reses).

West Usambara two-horned chameleon (Kinyongia multituberculata) at the Houston Zoo.

A Linne’s two-toed sloth (Choloepus didactylus).

Sally lightfoot crab (Grapsus grapsus) in Galapagos National Park.

Children crawl through a tunnel inside a huge aquatic exhibit at the Houston Zoo.

National Geographic Photographer and Speaker