IT sounds like a teacher's nightmare. Have you ever found yourself struggling to spot the difference between two similarly dressed identical twins?
Well, spare a thought for long-suffering staff at Kirkby College, Nottinghamshire. Incredibly, the school has five sets of triplets for teachers to tell apart.
The 12 to 18-year-old gangs of three, not all of whom are identical, are just one of those coincidences that make life at the school even more interesting, according to headteacher Lynn Parks.
Indeed, identification is not the only challenge arising from the school's unlikely intake. Group dynamics and sibling rivalry mean serious consideration has to be given to where the brothers and sisters are placed.
Mrs Parks said:"Some of the triplets wanted to be together, while some are adamant about wanting to go their own way. Where we can, we accommodate their wishes."
The girls who make up two-thirds of the Cantrill triplets deny being related and will not share the same friends at school.
Perhaps this stems from their living patterns at home. While their brother gets his own room, Carina and Leanne are forced to share a bedroom with two CD players, two mirrors and an imaginary dividing line.
The Wilsons, by contrast, get on very well, don't mind being in the same class and still occasionally wear the same clothes.
The siblings are being featured on an ITV documentary, called, appropriately enough, "Triplets", next Tuesday at 10pm.