They are a harbinger of summer and every spring they migrate here in huge numbers from north Africa and Europe - but now it looks like a few hardy red admiral butterflies are starting to stay here for the winter as well.
Latest survey results have revealed that red admirals were the big winners in the butterfly world this summer.
As late as the end of September, there were reports of as many as 20 red admirals counted at Belfast's Botanic Gardens.
According to the British Trust for Ornithology's (BTO) Garden Birdwatch, 2013 was a good year for many common garden butterflies, giving them a boost after a series of miserable summers.
But this year started off even better, with many species emerging earlier and in greater numbers than in previous years because of the mild spring.
The star species was the red admiral, which started showing up in gardens three weeks earlier than in 2013 and had been spotted in 42.4% of survey gardens by the end of August, a 26% increase from 2013.
By the beginning of October unprecedented numbers were being reported, BTO said.
Red admirals were reported from 14 survey gardens in Northern Ireland and were appearing at the end of August.
BTO said red admirals were increasingly being reported well into the winter, with more seeming to survive the winter instead of dying off or returning to their wintering grounds.
Clare Simm, from the Garden BirdWatch team, said: "We knew from anecdotal reports that this year would be another good one for butterflies, and it did not disappoint. As you can see, our volunteers do not just focus on birds, but also provide us with vital information on other wildlife groups too."
Northern Ireland butterfly recorder Ian Rippey said this year has been reasonably good for a lot of butterflies, although not exceptional, and said red admirals were being seen well into autumn.
Forty were reported at Mount Stewart in early September, with 10 in Millisle on September 16, he said.
"Red admirals are often seen well into autumn - it's something that has become a phenomenon over the last number of mild winters," the butterfly expert said.
Brown/black wings with red bands and white spots near tips of forewings. Undersides dark and mottled. A large and strong-flying butterfly which is common in gardens, may be found anywhere in Britain and Ireland. Starting each spring and through the summer there are northward migrations from North Africa and continental Europe. The females lay eggs, with fresh butterflies from about July.