What are sponges made out of(the ones you clean with?
just a very random question
Sponges are made from wood fibres or bubbles of plastic polymer. Most of the sponges have an absorbent material and are completely biodegradable. Check out http://en.wikipedia.org/wiki/Sponge_(material) for more details.
Natural sponges come from the ocean! They're SpongeBob!