I love guinea pigs, best composters in the whole world. Eat all the waste veggies, turn them into nice neat little pellets, all ready to go into the compost heap with whatever they decide they don't like (which isn't much). Alternatively I just move the guinea run and cut the lawn with the Flymo which sucks up all the poo, half-eaten bits, dried leaves falling off the trees etc, all ready to go onto the compost heap.