The double layers of cell membranes are made up of PHOSPHOLIPIDS.
The cell membrane, also called plasma membrane is made up of double layers of phospholipids. The Phospholipid is a type of lipid, which is made up of two parts, an hydrophillic head, and a hydrophobic tail. The hydrophillic head is made up of phosphate and glyerol while the hydrophobic tail is made up of fatty acids. The double layer of phospholipids serves as a barrier that allows only certain substances to enter into the cells.
Bats are very unique and interesting organisms, as they live all there life away from sunlight, they are considered to be the most advance of all the predators just because of having a sonar system inbuilt in there body system. While, they feast on there food outside the place where the remain most of the time and those places are caves.
Now, caves are more then just we exactly know, caves comprises of the different level of organisms and they play a very vital role in the over all balancing of the ecological system.
As, there are some insecticides, and other large organisms which then feast upon the bodies of bats corpses or when they are injured due to some reason. So, they play a vital role in the over all ecological food system inside the caves as well.
Organisms can be separated into different classifications due to many differences phenotypically or genetically. As we have progressed, research has shown differences allowing us to see bacteria and archaea as different organisms.