Michael Viney responds to readers' queries and observations on nature.
On a boat-trip down the River Erne, Co Cavan, we saw the remains of freshwater crayfish scattered on the walls of the three mill races. What creature was responsible? James Candon, Boyle, Co Roscommon
Probably a mink.
Beside a north Wexford beach in late July, I saw ragwort infested by swarms of beautiful moth-like insects with a black body and green, shiny wings with crimson dots, about three-quarters of an inch long. Peter Thompson, Arklow, Co Wicklow
They were cinnabar moths, which lay their eggs on ragwort on which the larvae feed. It was a bit late for egg-laying, which usually takes place in June but sometimes in July, with the larvae appearing in September instead of July and August.
Every morning at 7.30 a.m., a swan from the mill-pond beside us does a few circuits of the fields around us and over the house. Is it checking out the territory? John P. Convery, Crossgar, Co Down
Probably, and taking some morning exercise.
Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo; e-mail: viney@anu.ie. Include a postal address