What has affected the honeybee population?

1. pesticides: that are sprayed on crops and flowers

2. global warming: warm winters have caused plants to shift their schedules. when the honey bees come out of hibernation, the flowers they need to feed on have already bloomed and died 

3. pathogens carried by mites weaken bees

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.

Idon't know hope someone you