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Japanese zookeepers lost track of several squirrels after a typhoon last week felled a 120-year-old pine tree, which slashed through the netting of the animals’ enclosure. In the commotion, 30 of the bright-eyed, bushy-tailed rodents made a break for freedom.

The recovery of the lost animals has been astoundingly successful: As of Friday, zookeepers said, they had “recaptured” 38 squirrels, most of them captured in surrounding parkland. They were quickly returned to the Inokashira Park Zoo.

So why the mysterious additional squirrels? Zoo officials have come up with a number of explanations. According to Japan Today, zoo official and animal biology specialist Hioshi Mashima said on Friday, “More than 40 squirrels must have gotten away in the first place. There are no wild squirrels inhabiting this area. That is for sure.” Mashima said the zoo could not be precise on the exact number of squirrels it currently has in it possession “because they are difficult to catch, and they keep reproducing.”

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But another zoo official, Eri Tsushima, told the Japan Times on Friday that animal handlers may have actually swept up wild squirrels from outside the zoo’s walls, noting that the zoo implants a microchip in each one of its squirrels and that each animal taken into captivity would be checked for the microchip.

Meanwhile, the zoo continues to get calls about runaway squirrels at large in Tokyo. “We still receive about four to five reports a day from witnesses,” says Tsushima. “We will continue to set traps as long as people keep reporting the squirrel sightings to us.”

This is not the first time Tokyo’s Inokashira Park Zoo has had a jailbreak. A month ago, zookeepers recaptured a fugitive Humboldt penguin that had spent 82 days swimming in Tokyo Bay, garnering a massive media following. The zoo is now holding a naming contest for the penguin, who is still known merely as penguin No. 337.

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