Are reptiles cold blooded?

Reptiles are often refereed to as 'Cold blooded' animals, which is an over simplification of a complex arrangement. Reptiles are Ectotherms, this means that they rely on external heat sources to maintain a constant body temperature. Because they have no internal mechanisms to generate heat, they must seek out warmth .

Reptiles are therefore most numerous in tropical or hot and arid areas where the air temperature is high as they do not want to spend a lot of time warming up.

As they do not maintain a high body heat, they require far less food than mammals or birds of a similar size and so the have been able to successfully colonise areas that cannot sustain high numbers of birds and mammals.