But for the past fortnight it is the question Liz Lammers has been asking visitors to her St Clair home - to the disbelief of most.
"It's been a lot of fun."
However, she was quick to point out the monarch butterfly was not a pet: she was just too afraid that letting it out during recent cold weather would lead to its death.
"It's been so cold out there, I didn't know what to do," she said.
Two butterflies that had emerged earlier from a swan plant were quick to leave the house, but this one seemed happy to stay, even when doors were left open on the few warmer days, she said.
After seeing butterflies being fed sugar water at Otago Museum, she tried the same thing at home and found the butterfly enjoyed it.
"It's quite happy drinking out of the spoon. I can sit and have breakfast and it'll be feeding away in the other hand."
She left a saucer out with sugar water on it when she was at work, and the butterfly spent most of its time sitting on the house plants.
