An abandoned cat gave birth just seconds after being brought into the RSCPA's rescue centre in Hull.
Stray cat Nina had her first kitten in a tattered old box in the front reception.
This was closely followed by two other kittens, who have since been named Natasha, Norman and Nicola by charity staff.
Receptionist Amanda Nightingale could not believe it when she saw the kitten being born.
"A man came in carrying a dilapidated old box and said he had brought in two cats from his shed," she said.
"I opened the box and saw the mum, the dad and half a kitten.
"I couldn't really do anything except leave her in the box.
"We took the male cat out in case he was upset and attacked the mum or the kitten.
"Later, in a cage, she gave birth to two more kittens.
"It was a bit of a shock."
Staff say the number of abandoned and neglected animals is on the increase, with Hull becoming one of the worst areas for rejected pets.
The Hull and East Riding branch of the RSPCA has seen an increase in animals at its Clough Road shelter, but a decrease in donations.
To try to raise more money, the charity is opening a shop in Hull.
Hull RSPCA's general manager Alison Ripley said: "We're just sorting out the final details now, but we should be opening the shop in the next month or so.
"The legacies we get left and the general income for the charity is dropping all the time and we haven't been able to plug the gap.
"If we get a shop it will give us a sustainable income.
"We're hoping it will be a huge asset for us and generate about £15,000 a year.
"But unless we get the public support to stock it, that won't happen."
Alison explained there has been an increase in animal cruelty cases, with many pet owners refusing to pay vet bills.
She said: "Hull is one of the worst in the country for cruelty.
"A lot of it is people just not having the funds.
"They aren't taking their animals to the vets, so they are left suffering at home.
"They also aren't getting their animals neutered, so we're seeing houses crammed full of animals.
"We can see houses with 30 or 40 cats in them.
"People need to be more responsible with their animals and get them neutered if they can't afford kittens and puppies.
The RSPCA can offer a £30 contribution voucher towards the cost neutering to those on welfare benefits.
The RSPCA is now appealing for responsible pet owners willing to adopt some of their animals, and for supporters to donate items for the new store.
The shop will be stocked with clothing, soft furnishings, bric-a-brac, jewellery, toys, books, games, household goods and unwanted gifts.
Anyone wishing to drop off donations can leave them at the RSPCA base in Clough Road from 11am and 4pm Tuesday to Friday or from 11am to 3.30pm on Saturdays and Sundays.
To contact the centre, visit rspca-hull.org.uk or call 01482 341331.
