From the Link given in OP:


"Christopher, a lecturer at Royal Holloway University, cycles past the flock every day – but said he's never seen the creatures behave that way before.

"The sheep are usually noisy," he said.

"I go past them every day, but this day they were very still and calm.

"It was so quiet, like they were in a trance. It was very eerie."

Christopher said his wife Victoria and son Louis thought the photos were "nuts"..."

...
...