TELLING twins apart can be tricky at the best of times.
But staff at one Hull nursery have to do so with seven different sets of siblings.
Identifying who is who can be a difficult job, admits Sharon Cattle, manager at Fenchurch Street Nursery, where the twins are on roll.
"It does get confusing," she said.
"We call them each other's names sometimes. They get cheeky sometimes and start telling us they are the other one.
"The staff all think they are seeing double!"
Only two sets of the twins are officially identical.
"Even though there are only two confirmed identical twins, the others all look alike," said Mrs Cattle.
"They are all different personalities though and it is good to know them by their personality because it does get confusing.
"I have been working in childcare for 26 years and I have never known so many sets of twins in one place.
"It is really unusual."
The nursery has 98 children on roll.
Based in the Fenchurch Children's Centre, in Fenchurch Street, off Beverley Road, it takes up to 50 children at a time, meaning not all the twins are there at the same time.
Ages of the twins range from one to three.
Mrs Cattle said: "We started with one set in 2011 and in the past year they have just started coming in.
"We had three sets when I started and it just went from there. It's in the last year really when all of them have started coming in.
"It's like double vision. Every time we have a new set of parents and tell them what number set they are they are surprised.
"When we got them all together for the photo they loved it.
"It was amazing to get them together.
"The parents are aware of the number of sets in the nursery but don't always see them together, so it was nice for them all to get together and network and see them together."
Katie Laud, who is mum to three-year-old twins Jacob and Ethan, said: "I think it is very unusual.
"It was all very new to me when I found out I was having twins.
"Then all of a sudden you would start to see the odd set here and there but to have seven sets in one nursery is surreal.
"Getting them all together was a great experience because I got to speak to other parents and we all knew what each other was going through.
"It is challenging when you have one child but having two is a lot different.
"It is really fun and great but it can be challenging and to have other parents to speak to is great."
Mrs Laud says her boys are not at an age where they quite understand the notion of twins or how unusual they are in being one set of seven at the nursery.
"They think it is normal," she said.
"It is normal for them, but they think everyone has got someone like they have.
"They know they have always got each other.
"They don't always need to play together, but they always check where the other is.
"They have a close bond, they all do, and while they may not always do things together, they always check back in with each other every so often."