According to the classification of living things human beings belong to mammals. However, there is a great number of other different categories. The category of reptiles is one of them. The main difference lies in the way different processes proceed. First of all, it is a question of thermoregulation. Mammals regulate the temperature of their body with the help of difficult chemical processes inside their organism, which leads to the discharge of a great amount of heat. Reptiles just accommodate to outer temperature. Moreover, human beings and mammals have another unique feature which lies in the presence of hair and the way they feed their posterity.