A US animal shelter is dealing with a great big problem after a man arrived to hand over what he initially said was 150 mice.

However, the donor to the shelter in the state of New Hampshire later clarified that he had 150 containers of mice, not individual creatures.

He eventually turned over around 1,000 of the rodents to the facility in Stratham.

A mouse on a handler's shoulders
The New Hampshire SPCA said it has been overwhelmed by the animals (AP)

The shelter’s executive director said that before this event, the most creatures it had ever taken on a single day was 125 animals.

Lisa Dennison, executive director of the New Hampshire Society for the Prevention of Cruelty to Animals, said basic biology is making things worse. Mice breed early and often, and many of the rodents arrived at the shelter pregnant – and the effect on the facility is “crippling”.

Lined up nose to tail, the mice would span more than a football pitch. There are enough to give one mouse to every member of the US Congress and the 424-member New Hampshire state legislature combined.

“Even in the short time that we’ve had them, many of these mice have given birth,” Ms Dennison said. “It’s an exponential problem that keeps growing.”

A handler checks the mice
Many of the animals have been adopted by pet owners (AP)

Part of the shelter’s cat pavilion has been turned into a mouse hospital and hotel, with dozens of containers lined up on the floor, resting on top of multiple tables and stacked on shelves.

Just logging each mouse into the shelter’s database is a chore, never mind providing food, water and bedding.

Ms Dennison said of the logistics: “It does happen where you take a large number, but even when we took in 54 goats or we took in 39 cats, I mean, those are still large numbers, but much more manageable as you can imagine than hundreds and hundreds of mice.”

Other shelters have agreed to take some of the mice, and some are being sent to foster homes as the shelter seeks donations of food supplies. About a dozen mice were ready for adoption on Friday after being named by shelter staff and volunteers.

Mice in a glass tank
The shelter had initially expected 150 individuals – not 150 containers (AP)

Doug, Darrell, Dude and Deputy were waiting for homes in one tank. Others were given sweet-inspired names — Butterfinger, Junior Mint and Milk Dud, to name a few.

Elisha Murray heard about the shelter’s predicament from local news and decided to adopt four females named Kelly, Dee, Maxine and Eleven, despite having told her children last week: “No more rodents.”

“We’ve always had small rodents as pets – rats, mice, hamsters – so I just figured I could help out,” she said.

“We have the whole set-up, everything I need at home already – so I figured, what the hell?”