The Washington PostDemocracy Dies in Darkness

On routine house call, pest control finds 700 pounds of acorns in the walls

Nick Castro, a pest control technician, made a nutty discovery when he cut into the wall of a California home on Dec. 15, 2022. (Video: Gabriel Moore)
3 min

When Nick Castro received a call about an insect problem at a California home, the pest control technician figured a dead animal was stuck inside a wall. When he cut a hole in the wall to find it, however, Castro witnessed something he’d never seen in more than 20 years in the business.

Thousands of acorns spilled out of the wall, and more appeared whenever Castro stuck his hand into the hole. He soon discovered woodpeckers had stored tens of thousands of acorns, which he said weighed roughly 700 pounds, in a wall cavity.

“I was just kind of shocked and just wondering when it was going to end,” Castro, who owns Nick’s Extreme Pest Control in Santa Rosa, Calif., said. “We really expected maybe a couple handfuls of it, at most, but nothing like that. There’s no way you can even account for that.”

Late last month, Castro, 42, shared photos of his acorn discovery on Facebook, where his small company’s page received hundreds of likes and comments.

Since he began working in pest control in high school, Castro said, he has watched many animals outmaneuver people to enter their homes and access their food. He once caught about 60 rats that scurried through a drain and chewed through a floor to reach a dog’s food bowl, he said.

A squirrel hid thousands of walnuts under the hood of a man’s truck. It wasn’t the first time.

Around Dec. 15, Castro said, a customer complained that maggots and mealworms were emerging from the wall in their Glen Ellen, Calif., home. Castro figured the service would be typical: He would remove a dead animal and fix the hole it entered.

After arriving at the house around 8 a.m. with two colleagues, Castro used a drywall knife to create a 4-by-4-inch hole in a second-floor bedroom’s wall. Acorns rushed out of the pocket. Castro said the pile stood about 20 feet high.

“You can say this bird was a little bit of a pack rat,” Castro said as he sifted through acorns. “This is crazy. It’s just not stopping.”

Castro carved three more holes to unleash the acorns, which he said filled eight garbage bags. As Castro and his crew carried the bags to their truck, they noticed woodpeckers and acorns scattered outside the house.

The birds had pecked hundreds of holes on the chimney stack, where Castro said he believes they stashed and snacked on acorns for two to five years. Castro speculates the acorns then slipped through a wall cavity, where he discovered them.

Paul Bannick, who has written two books about woodpeckers, said the acorn woodpecker, a species common on the West Coast, often amasses thousands of the nuts for winter. Acorn woodpeckers can drill small holes in almost anything — trees, birdhouses, cabins, houses — to hoard food, he said.

Acorns are vital for the birds’ breeding, Bannick said, because they help female woodpeckers stay plump and healthy throughout the winter.

“It’s a compulsive process,” said Bannick, a director at Conservation Northwest, a Seattle wildlife preservation organization. If the woodpeckers know there are acorns on the ground, “they’re going to collect and store as many as they possibly can.”

After Castro witnessed woodpeckers’ obsessions firsthand, he repaired the areas the birds damaged and added screens to cover wood sections on the home’s exterior. Following his eight-hour job, Castro trashed the acorns.

While he offers follow-up services, Castro said the homeowners haven’t reported any problems so far this year.

“But if anything like that does happen and they come back,” Castro said, “we’ll come back free of charge.”