A poikilotherm is an organism that its temperature fluctuates based on the temperature of its surrounding.
The English term 'homeotherm' means an animal that has a body temperature that is relatively constant and independent of the environmental temperature
Any animal (mammals, birds) that have some sort of internal heating device, keeping their internal temperature constant.
Usually by 'basking' in direct sunlight, thus absorbing warmth. If they get too warm, they find a cool place to rest.
An ectotherm is an animal that controls its body temperature through external means. As a result of this it is dependant on environmental heat sources (such as basking in the sun) and has a fairly...