If the animals enjoy taking a bath then human beings are not at all an exception. The only difference is that the human beings can alter the temperature and some other qualities of water such as its smell.
The skin is made up of epidermis and dermis. The layer below this is that of cellular tissue. Besides covering the body the skin acts as an excretory organ too. The skin helps in regulation of the temperature by eliminating perspiration from the skin through the pores. Now these pores should be clean. If they are not clean the sweat cannot come out and can cause skin disorders and diseases. Thus a good bath is necessary for a healthy skin.