A group of Lancashire pupils had their return journey from a trip to France delayed last week after two would-be illegal immigrants were found clinging to the underside of their coach.
The children - from All Hallows Catholic High School in Preston - discovered first hand the desperate measures to which migrants will go to gain entry to the UK.
When the 40 Year 9 pupils and six members of staff stopped at a supermarket in Calais, coach driver Bob Barrett spotted a pair of feet poking out by the front wheel arch.
The police removed the man and took him into custody and then allowed the coach to continue home from the half-term trip to war graves in Le Touquet and St Cecile.
But at passport control, UK Borders Agency staff searched under the coach and found another stowaway clutching the pipes so tightly he had burnt his hands.
Christopher Riding, the school's headteacher, said: "For some of the children, it was a bewildering experience. They couldn't really understand why individuals would go to such lengths to enter the country."
The party was not delayed significantly and even managed to arrive back in Preston slightly early, full of praise for Mr Barrett.
"I tried to get the immigrant out myself with a brush handle. These things have got to be done," the coach driver said.
"When he wouldn't budge, I phoned the police, which was difficult as I don't speak French and they don't speak English. They had managed to force him out just as everyone returned to the coach."
"The teachers were stunned," Mr Barrett added. "I was glad I had clearance from the French authorities. These incidents aren't as uncommon as you'd think. I could have been fined up to pound;2,000 or had my licence and passport taken away from me."
Since the group's return, the events have been discussed in lessons at All Hallows, giving teachers the opportunity to discuss issues around immigration.
Mr Riding said: "The trip was not negatively affected by what happened at all. The children have actually learnt a great deal."