Explain how insects thermoregulate and cite an example of how insects can raise their temperature.

Choose between the two following prompts for this discussion:

Polyphenism is observed in aphids. Define polyphenism and give another example of an insect in which polyphenism is observed. Give specific information regarding the stimulus and the cause.
What is thermal biology? Explain how insects thermoregulate and cite an example of how insects can raise their temperature.