And so the monkeys at London Zoo have had to be retrained after they began snatching visitors' mobile phones.
Zoo visitors were holding out the phones to take pictures or video of the squirrel monkeys in their walk-through enclosure.
But they found that the inquisitive primates could not resist the devices' ring tones and bright lights.
A training program using old mobile phones covered in a sticky substance that the monkeys dislike was implemented to stop the animals taking off with the mobiles.