WE HAVE been intrigued by the masses of soil dug up by moles and left in hills (or heaves as they are known) on English private lawns or in the fields.

Moles are able to shift up to 6kilograms of soil every 20 minutes, so their activity is quite noticeable. It's more difficult to see the actual animal, however, so we were fascinated to find a freshly dead mole beside some diggings.

June is the time when mother moles drive their offspring out to find vacant territory of their own.

During this adventure, the young mole wanders about, often above ground, where it is exposed to many dangers. Judging by the amount of adjacent earthworks, vacant places are scarce and our mole must have died in the attempt to find one.

It was plump and covered in fine, velvety grey fur. The mole fitted comfortably in the palm of my hand and had tiny eyes, sharp canine teeth and front, large digging paws which resembled baseball mitts.

Some years ago, I was lucky enough to see a live marsupial mole that had been captured for genetic studies. It was a little smaller than the European mole and had golden rather than grey fur but had similar digging paws. Its eyes were not visible.

These animals live in Australia's inland desert country and little is known of their biology because they are so hard to find.

They are true marsupials, however, and many millions of years ago must have shared a common ancestor, that had a marsupial reproductive system, with other marsupials such as koalas, kangaroos and Tasmanian devils.

From that common ancestor, all the modern marsupials have evolved to fill a variety of ecological niches. It is fascinating that a similar ecological niche in the northern hemisphere was filled by another mammal but one with a completely different evolutionary past.

This is yet another demonstration of the power of natural selection.

Report koala sightings: UWS pager, 99629996.