system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Animals can only be impregnated during the blood but women is the opposite. 

Please help.
gpt
Because it's not the same blood. Women's bleeding gets rid of the lining of their uterus as part of the menstrual cycle. Animal bleeding happens as a result of the hormone shift when they go into heat, which is called the estrous cycle. Some other primates menstruate like people do, but most don't.

edit: seriously you guys can't understand this question?