Abandoned pets are a growing part of the military culture. Dogs and cats are dropped off in remote corners of the post at a rate of more than 20 a week. But the US Armed Forces are fighting back. Adopting a Big Brother approach, the military is implanting microchips in cats and dogs that live on government land - as much for animal control as for owner control. Says Fort Polk, La., Garrison Command Sgt. Maj. Ricky L. Jones of the soldier who abandons a pet, with the chip you can't hide." Fort Polk has used the chip to track down soldiers who have abandoned their pets and forced them to pay an adoption fee. "It's a way to control our stray animal population and protect our working force, too," says Capt. Steven Baty, a veterinarian at Fort Carson, Colo., where microchipping has been mandatory since 1998. The tiny chips, the size of a grain of rice, are injected under the skin on an animal's neck and contain a bar code that can be scanned and read by humane societies and veterinary clinics nationwide. The procedure costs about $15, takes two to three seconds, and is no more painful than a typical vaccination. Microchip enforcement varies by base. At Fort Polk, La., animal controllers are part of a weekly housing patrol, joining inspectors who check to make sure lawns are cut and that soldiers aren't violating housing regulations. The animal controller carries a portable scanner and runs the wand over dogs and cats, looking for numbers to light up the small screen. If the pets don't have a microchip, soldiers are warned, and if they don't comply, their animals are taken away.