The presents natural and physical line of body defense which protects vulnerable tissue and underlying soft from pathogens. Skin again serves as a physical barrier and as body defense against different invading pathogens. The skin has evolved with morphological features and helps to evade infections. For example, the sweat which is being secreted from sweat glands it has a large amount of salts and this sweat helps to attack any bacterial population includes removal of the uppermost dead-skin layer which removes microbes which are attached to it.
Wells can dry up or become contaminated, this question isn't really clear so it's hard to say. It can become contaminated by underlying salt water, heavy metals, or man-made pollutants. Wells also dry up frequently and become unusable.
Modern alligators have many adaptations to make them well suited for their wetland environment. These plates are extremely thick and well adapted for their environment. Their skin camouflages very well with their environment and along with the bulging eyes this makes them look like a log!
