Collaring cats - Telegraph Cats will be kept indoors all night, and even have bells attached to their collars, as in Australia, if wildlife campaigners have their way. The cat curfew would help save the 200 million songbirds that are killed by them each year, according to an Essex wildlife centre. Hedgehogs, whose numbers have fallen from 30 million a generation ago to fewer than a million, would benefit too, the argument goes, since cats hunting at night pounce on their young. Yet in the wildlife war, everything depends on whose side you are on. On the Hebridean island of South Uist, hedgehogs are blamed for eating the eggs of wading birds. Hundreds of hedgehogs there have been culled or evacuated to bewilderingly foreign territory. As for cats, they may not be wild, but they are the next best thing. Some pet owners fear that, if cats are tagged, they'll be coming for our dogs soon.