Conversation so far:
what did they do before tampons and pads
Before the disposable pad was invented, most women used rags, cotton, or sheep's wool in their underwear to stem the flow of menstrual blood.
what are some alternatives to tampons and pads
Alternatives to tampons and pads include menstrual cups, period panties, and menstrual sponges.

Question: what are menstrual sponges
Self-contained rewrite: what are menstrual sponges