Even though frogs and roads live in a wide variety of habitats, their daily and seasonal activity patterns are limited because they have permeable skin, which makes them prone to drying out water evaporates from their bodies much more rapidly than in land animals whose skin is covered with scales, feathers, or hair. To reduce evaporative water loss, most species limit their activiity in she night, whwn the relative humidity is higher and temperatures are cooler. During the day ( and at night during dry periods ). Frogs and roads take shelter in moist ureas under rocks, boards, and other objects, and by hiding in burrows some of these burrows they make themselves. While others are inherited from a shared with other animals. If direcly expored to dry conditions, they may ruck in their legs and roll up or hug the ground, minimizing the surface area incontact with air. In extremely arid environments, numerous species estivate during the driest times of the year, resting in burrows and lowering their metabolic rates in order to survive the dry period.
One advantage of having permeable skin is that the skin can act as an important respiratory organ, directly passing oxygen from the air to capillaries. This is especially helpful during inclement weather respiring through the skin takes some load off the lungs, heart, and circulatory system and also helps frogs and toads survive long periods without eating.
