Would an ectotherm or an endotherm be more active on a cold night

An endotherm would be more active on a cold night compared to an ectotherm. Endotherms are capable of producing their own body heat and are therefore more able to endure cold environmental conditions. Ectotherms rely on external sources for body heat and therefore will be less active (due to reduced metabolic processes) on a cold night.

The answer is the ulna nerve