has been installed as part of the "house rules" that accompany a famous annual migration of seals to Lincolnshire.
Thousands of seals migrate to Donna Nook, near North Somercotes, to give to birth to pups on its dunes and sandbanks every year, the Grimsby Telegraph reports.
The event attracts visitors from all over the UK.
However, visitors have been asked to observe some house rules, the newspaper reports.
These include staying behind the security fencing
in the viewing area, not getting too close to the seals and never to touch or feed them.
Rachel Shaw, of Lincolnshire Wildlife Trust, told the newspaper that Donna Nook can get very busy.
"We had 4,000 visitors on Saturday and Sunday.
"The road is just a narrow, single-track and the car park fills up very early in the morning."
According to the trust's pupping update, by Monday November 1st, 35 pups had been born, but by Monday November 8th this had bloomed to 160.