Why are very small animals rarely found in polar regions? Give reason.

Explanation

Thermo regulation is energetically expensive for small organisms like shrews and humming birds. Heat loss or heat gain is a function of surface area. Since small animals have large surface area relative to their volume, they tend to lose body heat very fast when it is cold outside then theyhave to expend much energy to generate body heat through metabolism. This is the main reason why very small animals are rarely found in polar regions.