The epidermis, or the outermost layer of skin, is constantly changing. Skin cells from the lower layers make their way to the surface and eventually fall off; a process known as natural exfoliation or desquamation. These cells are held together by protein rivets called desmosomes, and at the appropriate time, enzymes in the skin dissolve the desmosomes to allow the cells to separate and shed one-by-one. When skin is too dry, the enzymes that degrade desmosomes cannot function properly, which leads to clumps of cells that shed together, instead of single cells that shed invisibly. These clumps can be seen as flakes or scales.