Some animals cannot perspire (sweat) like humans can. When water evaporates it cools the body. Animals, like dogs, open their mouths and exhale water vapor. This has a similar effect as sweating.
Some fish swim with their mouths open to help them breathe better. By opening their mouths, they can take in more water and extract oxygen from it as it passes over their gills. This can be especially helpful in low-oxygen environments or when they are swimming at high speeds.
The reason why dogs and birds pant through their mouths and elephants flap their large ears, is to control (reduce) their temperature. Some animals can sweat through their skins and cool themselves as this sweat evaporates from their skin. However, dogs, birds and elephants (and perhaps some other animals) can not sweat so they either evaporate water in their mouths or pump blood into their 'radiator' sized ears to cool themselves.
They have big mouths to get lots of foods.
they open their mouths, bite some food, chew, then swallow
Low muscle tone in the facial muscles
NO there is no animal that have their mouth above their eyes
They do that to try and catch some pray, if any happen to swim or fall into their mouths.
They open their mouthparts, grasp some food, pull it into their mouths, "chew", and swallow.
Actually, the short answer is "No". Not all animals have mouths.Adult Luna Moths do not eat or have mouths. They emerge from their cocoon as adults only to mate. As a result, their adult life span is about 1 week.
There many plants and animals that have adapted to their environments. Humming birds for example have developed tube-like mouths to eat.
Some People do open mouth
some mammals sweat, but the dog pants to keep cool