The parenthetical + en and + is invoke further operations on the verb bite that transform it into is being bitten, and ultimately Kate is biting Mark is 'transformed' into Mark is being bitten by Kate.
I was being bitten by tiny insects.
Additionally, some people are being bitten by water snakes.
He's been bitten so many times that he's immune to the poison.
"We are being bitten alive by the things," said one protester.
"The worst was being bitten by black flies when we were doing the tai chi," Ms. Mirren said.
Was I prejudiced against the author I read in the resort of Kalbarri because I was being bitten to death by mosquitoes?
If the barely varied, incessantly jogging rhythms sometimes gave one listener the impression that he was being bitten to death by woodpeckers, well, that may have been no more than his personal Hindemith problem.
She's been bitten in the line of duty, and a couple of years ago a Labrador retriever rammed one of her knees from behind, putting her in a wheelchair for seven months.
