Hey cats can be useful I just read this the other day.

A German inventor has angered animal rights activists with his answer to fighting the soaring cost of fuel -- dead cats.
Christian Koch, 55, from the eastern county of Saxony, told Bild newspaper that his organic diesel fuel -- a home-made blend of garbage, run-over cats, and other ingredients -- is a proven alternative to normal consumer diesel.

"I drive my normal diesel-powered car with this mixture," Koch said. "I have gone 170,000 km (106,000 miles) without
a problem."

The website of Koch's firm, "Alphakat GmbH", says his patented "KDV 500" machine can produce what he calls the "bio-diesel" fuel at about 23 euro cents (30 cents) a litre, which is about one-fifth the price at petrol stations now.

Koch said around 20 dead cats added into the mix could help produce enough fuel to fill up a 50-litre (11 gallon) tank.

But the president of the German Society for the Protection of Animals, Wolfgang Apel, said using dead cats for fuel was illegal.