In this method of respiration, oxygen from the air is drawn into a frog's body by the blood vessels that lie close to the skin. Waste gas and carbon dioxide are also released the same way. In order for all the transfer to take place the frog's skin must be moist. Croaking and chirping noises you hear near ponds usually occur on spring or summer nights. During rainy days you may see frogs hopping through grass or among the plants of a garden.
Most tree frogs are smaller than bull frogs and green frogs.
They have skinny tummies and long legs. They have wide sticky disks on their feet that help them climb up trees and branches. An important skill to tree frogs is climbing. Different skin colors are created by changes in the pigments within a frog's skin. On bright, hot days frog's skin becomes lighter in color.