system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come mosquitos come back after winters over, why aren't they all wiped out?
gpt
Those aren't the same mosquitoes from the year before you're seeing, those are the larvae that have spent some time in ponds and whatever pools of standing water are around, that have pupated into adults. 

The warmer weather triggers them into the next stage, and then the adult mosquito females consume blood to help in the development of her eggs.