It's the end of the line for cheeky monkeys who've been stealing mobile phones from zoo visitors.
The bleeps and bright lights of the phones were tempting the squirrel monkeys at the barrier-free enclosure at London Zoo.
Keepers had to teach the nosy creatures to leave phones alone - by covering some unwanted ones with sticky mustard!
The monkeys hate dirt and were put off touching the phones, returning to their usual habits - sleeping and eating.
The monkeys started their naughty nicking when visitors to the walk-through enclosure - designed to look like a Bolivian forest - would hold out their camera phones to video or take photographs.
Malcolm Fitzgerald from the zoo said: "The new barrier free enclosure means the monkeys are in closer proximity to visitors.
"It's important that the monkeys maintain their natural behaviour and training them not to go for visitors' phones was essential to achieving this."