Platypus turns 25 at a Melbourne zoo

The world's oldest platypus has celebrated her 25th birthday with a morning scratch at a Victorian zoo.

Fleay celebrated the quarter-of-a-century milestone on Wednesday at Healesville Sanctuary, with keeper Dr Jessica Thomas giving her a birthday scratch.

While the mammal might be an "old lady" in platypus years - with most living only to about 20 - Fleay still plays in the waterfall in her exhibit and belly-flops into the pond.

She loves to sleep-in, enjoys eating black worms and often gives her keepers a growl.

Fleay has lived at the zoo since 1993 and is named after a former sanctuary director David Fleay who bred the first platypus to hatch in captivity in 1943.