HE took his time but at last Larry the Downing Street cat has earned his money and caught a mouse. Larry was recruited to No 10 in February in an effort to deal with its rodent problem. And while the four-year-old tabby rapidly won the affections of David and Samantha Cameron and particularly their children he appeared to lack the killer instinct. dm Week after week went by with no sign of any dead rats, mice or indeed anything, birds included. However, all that changed on Friday when Larry was seen climbing in through a window from the Downing Street garden with a mouse in his mouth. Seemingly happy to announce mission accomplished Larry dropped his briefly twitching catch at the feet of No 10s 'garden girl secretaries. There were one or two squeals before the cats good work was recognised. Larry was smothered with pats of congratulation from staff, mainly in the hope that it would spur him on to greater deeds, and catch some of the black rats seen scuttling across the lawn. Indeed, the cat-and-rat saga that has plagued Downing Street inspired Samantha Cameron to sketch her own version of events with Larry eyeing his quarry outside the door of No 10. She did the drawing for the Winnicott Trust, which supports babies and their families at two London hospitals, St Marys and Queen Charlottes. Fridays catch was reward for the Camerons patience. When they got Larry from Battersea Dogs & Cats Home in February, the Prime Minister said the cat had been 'highly recommended to him. Larry had a 'very strong predatory drive and high chase-drive and hunting instinct, developed during his time on the streets. But until last week, his only 'prey in No 10 was human. When ITN political reporter Lucy Manning went to make a film about Larry, he lashed out at her, scratching her four times before leaping to the floor and making a run for it. Worried at his lack of interest in dishing out the same treatment to rodents, staff resorted to some motivational 'training by encouraging Larry to play with a toy mouse. Larry is the latest in a long line of Downing Street cats, known unofficially as Chief Mouser to the Cabinet Office. When Margaret Thatcher was PM, a stray called Humphrey was adopted after wandering into No 10. He remained throughout the administration of John Major, but was 'retired after Tony Blair won power in 1997, amid reports that Cherie Blair did not like him. DM