Ten overweight hedgehogs have been put on strict diets after they got so large they were unable to curl into a ball to fend off predators.

The hedgehogs, which are under the care of Ramat Gan Safari Zoo in Tel Aviv, have had to go on strict diets and exercise regimes, according to Reuters, after they were rescued from the street - where they had been snacking on food from bins and meals left out for stray cats.

One adult male called Sherman was 1.6 kilograms (3.5 lb) when he arrived at the Zoo two months ago, after he was found struggling to walk. Weighing in at almost double the average weight for a hedgehog his age, zookeepers described him as "too fat" to walk.

"He’s too fat to go back to the wildlife [sic] right now so until he loses enough weight we are looking after him and keeping him busy and exercising him," said zookeeper Becka Rifkin.