Glass frog

The glass frog has a translucent skin that can offer you a clear view of its internal organs, such as its heart and liver. Researchers do not know much about these animals because they are quite difficult to find and collect, especially because of their appearance. 

As you can see, they are really good at camouflaging. This species of frogs range in size from twenty to thirty millimeters, but it depends on the species because some of them can be larger than that. 

The glass frog is nocturnal, which means that they are active during the night. Their feeding habits take place while they are active during the evening, but they can also feed during the rain showers in the daylight hours.