To celebrate their 98th birthday, Mosgiel sisters and identical twins Elsie Fagg and Cora Wright swapped cards, cash and good-natured teasing.
The pair gave each other cash in a card on their birthday yesterday.
The sisters had the tradition of whoever gave the card first, the other took out the cash and returned it in another card.
Mrs Fagg said the secret to living a long life was simple.
''Pills,'' she said.
''It's the truth. They keep you around longer.''
The twins had longevity in their genes as they had an aunt who lived to 101.
The sisters (nee Wells) were born and raised in Milton, Mrs Wright said.
''I was born first. I'm the oldest by half an hour.''
Mrs Wright often reminded her sister of the pecking order and the pair enjoyed some good-natured teasing, Mrs Fagg said.
Being a twin had advantages, the sisters said.
''At times,'' Mrs Fagg said.
''We don't always agree.''
The advantages of being a twin were greater when you were young, Mrs Wright said.
''You get a lot of notice taken of you when you're wee,'' Mrs Wright said.
In their youth, the sisters tried to trick people by pretending to be the other.
The sisters live at Mossbrae Healthcare in Mosgiel - Mrs Fagg since 2008 and Mrs Wright since 2013.
At the rest-home, the sisters will celebrate today by sharing afternoon tea with scores of family members, spanning the generations to great-great-grandchildren.
Both sisters had four children - two boys and two girls each - and both lost their husbands ''too early'', they said.
Twins ran in the family as some of the grandchildren and the great-grandchildren were twins.
