Two squirrels who boarded a rush hour train to Gatwick forced operators to cancel the service.
The squirrels jumped on the Great Western Railway (GWR) 8.54am train from Reading to Gatwick on Monday, forcing passengers to flee to other carriages.
The passengers alerted staff, who tried to lure the squirrels off the train at Redhill with snacks, before trying to force them off with brooms - but to no avail.
They subsequently called the journey off entirely.
It may have been disruptive, but a GWR spokesperson certainly saw the funny side.
"We can confirm that the 0854 Reading to Gatwick was terminated at Redhill after a couple of squirrels boarded the train at Gomshall without tickets, breaching railway byeclaws," the spokesperson said.
"We attempted to remove them at Redhill, but one refused to leave and was returned to Reading to bring an end to this nutty tail."
