Michael Viney responds to queries and observations on nature.
Having suffered a major infestation of cabbage white caterpillars last summer, my purple sprouting broccoli seems to be still harbouring a few live specimens. Is it usual for them to overwinter in this way? Pat Little, Arklow,Co Wicklow
Very strange. They usually overwinter as pupae.
I watched two herring gulls in Trinity College which appeared to be walking or running on the spot, and every so often they would make a desultory peck at the ground. Conor McCarthy, TCD, Dublin
They were drumming up some prey, insects or worms.
Recently, squirrels have become a feature in this area. Is this because they have a ready source of food on bird tables? Barbara Clear, Foxrock, Dublin 18
Bird tables attract squirrels but they have been moving into the suburbs because the trees that they like for seeds and shelter grow there.
• Send observations to Michael Viney at Thallabawn, Carrowniskey PO, Westport, Co Mayo; e-mail: viney@anu.ie (include a postal address)