Closely related to reptiles, the amphibian class includes frogs, toads, salamanders, and newts.  Contrary to their reptile kin, amphibians tend to have slimy skin and favor cooler areas, generally away from direct sunlight.  Amphibians can be found on every continent of the world, aside from Antarctica.  The biodiversity is, by far, the heaviest in tropical rainforests, such as the Amazon.  Some amphibian species have, however, evolved to become extremely cold-tolerant.  American Wood Frogs, for example, can endure over 70% of their small bodies freezing for months at a time, continuing to survive in torpor (similar to hibernation) as long as the heart remains unfrozen (rather poetic, don’t you think?).  Amphibians are absolutely brilliant insect control!  Aquatic species and tadpoles alike eat untold numbers of mosquito larva within the wetlands and ponds where these bloodsuckers lay their eggs.  These special, slimy creatures do have extremely permeable skin, however, making them far more susceptible to toxins than many other creatures.  Unfortunately, this includes many if not all insecticides and the deet within commercial mosquito repellant.  Many of these chemicals kill or deform frogs / toads, causing our natural mosquito eradicators to disappear.  As mosquitoes continue building a tolerance to these chemicals and amphibians disappear, we open the door for terrible outbreaks of mosquito-born disease (not to mention all the itchy bumps)!  Please only use natural insect repellants (such as lemongrass) and discourage the dumping of toxic mosquito chemicals, otherwise mosquito populations will continue to grow, unchecked.  We need our amphibians!!