SINGAPORE (Reuters) - With monitor lizards, snakes, and bats prowling their parks, residents of tropical Singapore are no strangers to the occasional animal ambush. But it's not the iguanas or squirrels that have locals up in arms -- it's the monkeys. Gangs of long-tailed macaque monkeys have been causing havoc in housing estates bordering nature reserves; stealing food and brawling on the streets. "They roam the estate in groups of up to 20 &- rampaging the estate and turning over dustbins," one irate local wrote to the national paper in October. "They enter the house, open cupboards, steal food and...