Eye on Nature/Michael Viney: Michael Viney answers some of your queries on wildlife around the country.
I have seen herons on the upper reaches of streams in the Wicklow mountains. What draws them to these streams, which seem too small for fish?
A few weeks ago I saw two skuas attack a small gull off the west coast of Co Cork. The gull was injured and was forced to land in the sea. However, a number of gulls drove the skuas off. Is it normal for gulls to defend their own?
Bob Curran, Dalkey, Co Dublin
As well as fish, herons are happy to feed on eels, frogs, newts, crustaceans, worms and insects, not to mention small rodents and small birds.
The mobbing behaviour of the gulls is a natural way to drive off a predator, shared by many other birds.
I noticed a woodlouse (timber pigs they call them here) walking across the carpet. I picked it up and was surprised when several snow-white dots fell to the floor. She seemed to be carrying a dozen tiny miniatures clinging to her undersides. Was she feeding them?
On September 8th I was watching several red admiral butterflies enjoying my herbs when one landed on my hand for several seconds, giving me time to examine it closely. It was a midget, barely the size of my thumbnail, but perfect.
Muriel Colburn, Rosscarbery, Co Cork
In the summer breeding season, the woodlouse lays eggs in a liquid-filled pouch under her body. They hatch in a month, the liquid disappears, and the little pale woodlice - each the size of a grain of rice - leave in a few days.
The midget red admiral is a startling observation. Some butterflies, such as the holly blue, can vary in size due to food supply at caterpillar stage, but I have never come across a reference to tiny red admirals.
On a holiday in South Wales in August, we came across a long line of dead jellyfish on Pendine beach in Carmarthenshire. They were between one and two feet across, including their "tentacles".
Jane Harvey, Abbeyleix, Co Laois
It was the Rhizostoma octopus, which is found all around our coastline.
On Mullaghcleevan in the Wicklow mountains I saw a flock of 50 to 100 ravens (see illustration). Why were they flocking and where would they have got enough food for so many?
Larry Gordon, Tallaght, Dublin 24
The flocking of ravens takes place mostly in autumn, in order to form a communal roost, particularly in remote areas. They also flock where there is a good food supply. Ravens are carrion-eaters and congregate where there might be dead sheep or deer.
A caterpillar appeared on our driveway early this month. It was seven to eight centimetres in length, green and yellow, with a scale-like appearance in its body segments, and an odd horn at one end.
Michael Jeffers, Naas, Co Kildare
It was the caterpillar of the death's head hawkmoth. The moth is very beautiful. It has a yellow body with a blue, longitudinal stripe and a yellow marking like a skull on its black thorax. The wings are like a brown paisley shawl. It is an occasional summer immi-grant here, and there were many reports of it this year.
Early in September in the Kinsale estuary I spotted an all-white heron. At first I thought it was an egret, but it definitely was a heron.
Anthony O'Sullivan, Cork.
It could have been the great white egret, which occasionally visits the south coast.
In a newly-dug drain leading to a garden pond, we found what appeared to be large dark-brown leeches, about three to four inches long. They had a sucker-type end, which they used for anchorage, and a pointier front end, and could elongate their bodies. Are they leeches and what do they feed on?
Ruth O'Dwyer, Damerstown, Castlecomer, Co Kilkenny
They were probably horse leeches. They suck the blood from various creatures that live in or around water and swallow small invertebrates whole. Despite their name they do not attack horses or any mammal.
In August I found, on the underleaf of a young oak, about 20 grey/blue eggs, obviously of some moth or butterfly. In mid-September they were still there.
Deirdre Brennan, Dalkey, Co Dublin
They could have been the eggs of either the scalloped oak moth which lays its eggs in August, or the August thorn moth which also lays in autumn, both of which do not hatch until the following spring. When they pupate next June or July take some in and see what emerges.
Michael Viney welcomes observations sent to him at Thallabawn, Carrowniskey PO, Westport, Co Mayo; e-mail: viney@anu.ie. Include a postal address.
Another Life will resume on October 11th