The red-eyed tree frog (Agalychnis callidryas) is an arboreal hylid native to Neotropical rainforests where it ranges from Mexico, through Central America, to Colombia. It is sometimes kept in captivity. The scientific name of the red-eyed tree frog, A. callidryas, comes from Greek words kalos (beautiful) and dryas (a tree or wood nymph). The species has red eyes with vertically narrowed pupils. It has a vibrant green body with yellow and blue with vertically striped sides. Its webbed feet and toes are orange or red. The skin on the red-eyed tree frog's belly is soft and fragile, whereas the back is thicker and rougher. Red-eyed tree frogs have sticky pads on their toes to cling onto leaves. Red-eyed tree frogs inhabit areas near rivers and ponds in rainforests and humid lowlands on the Atlantic slopes from southern Veracruz and northern Oaxaca in Mexico, to central Panama and northern Colombia. They also live on the Pacific slope in southwestern Nicaragua and southwestern Costa Rica to eastern Panama. The optimum temperature for red-eyed treefrogs is 24–29 °C (75–84 °F) in the daytime, and 19–25 °C (66–77 °F) at night. Phyllomedusine treefrogs are arboreal, meaning they spend a majority of their lives in trees; they are excellent jumpers. Red-eyed tree frogs are not poisonous and rely on camouflage to protect themselves. During the day, they remain motionless, cover their blue sides with their back legs, tuck their bright feet under their bellies, and shut their red eyes. Thus, they appear almost completely green, and well hidden among the foliage. The large red eyes serve as a defensive adaptation through deimatic behavior. When a red-eyed treefrog detects an approaching predator, it abruptly opens its eyes and stares at the predator. The sudden appearance of the red eyes may startle the predator, giving the frog a chance to flee.