..they could also found the place safe for overnighting and /or nesting (they do it on ground, preferably elevated. I think that the species is Larus canus (Mew gull)?
Mary MacADNski: They are enjoying the freshly dug worms. A real banquet laid out for them. We have many gull species but I am not knowledgeable about them. I love them though and have lots of photos of them in my archives.