Here in Britain we don't do large, showy wildlife: there are no bears, no wolves and very little in the way of big cats wandering our countryside. The wildlife we do have veers towards the cuter side of the animal spectrum – and top of that list has to be the hedgehog. But hedgehogs in the UK are not exactly thriving: in the last decade, numbers have dropped 25% and are at an all-time low. You could try pinning the blame on farmers – changes in farming practice haven't exactly helped the hedeghogs' cause – but before you do, bear in mind that most hedgehogs live in suburban areas. It's much more likely to be developments in domestic gardening methods that have caused numbers to tumble.
Why should we care?
The biggest mistake people make about hedgehogs is to regard them as little more than flea-ridden, spiny rats. A healthy hedgehog won't have any more fleas than any other animal of a similar size. And they share more genes with moles and shrews than they do with rats, mice or squirrels.
Just like the shrew and vole, the hedgehog is an insectivore with a voracious appetite – an adult can easily eat up to 200g of insects a night. That means it would take a single hedgehog only three months to munch its way through a slug-infested garden measuring the UK average of 90 square metres. Which is just as well: the average slug population can take that time to breed back to its original size.
It may not come as a surprise that they're not called hedgehogs for nothing: they really do like to hang out and seek their prey in and around hedges. However, the poor hedgehog is effectively barred from many potential habitats by perimeter walls and fencing. And if they do find a way in, we need to put in a bit of effort to encourage these valuable pest controllers to take up residence.
Meticulously tidy gardeners may recoil at the idea of doing less gardening and leaving grass long and piles of leaves all over the place. But if you want to provide habitat for a range of species, to ensure the hedgehog has a varied diet, that wildlife won't care what it looks like.
Leaves can be mounded up to turn into mulch or leaf mould, while leaving grass longer will help biodiversity – if need be, cut paths through the long grass to make a potentially scruffy-looking, hedgehog-friendly environment more appealing to fussy humans. A well-positioned pond will provide drinking water and, as long as they can escape were they to fall in, make a valuable addition to the hedgehog-friendly garden.
Log piles and dry stone walls (with tailor-made gaps for hedgehogs to get through) can also be home to a multitude of creatures that feature on the hedgehog's menu. Garden designer Chris Eves, of Eves & Lewis Landscape Design, takes a pragmatic approach to wildlife gardening, and sees the traditional log pile, say, as a wasted opportunity. "You may as well bung a seat on it," he says.
A prickly expert
I asked Hugh Warwick, a leading hedgehog expert and author of the brilliant A Prickly Affair: The Charm Of The Hedgehog (Penguin), how best to encourage these creatures into our gardens. "Hedgehogs need three things," he says. "Food, water and shelter. And pretty much all of those can be achieved with a good compost heap. If that's not practical, then think how you can mimic a hedgehog's ideal home, which is – have a look at the name again – yes, a hedge."
Warwick stresses that the hedge doesn't really need to be literally a hedge. "Shrubs or brambles that are close to the ground and under which a hedgehog can nest [will do], along with leaf litter to make the actual nest."
Leaves are also an important food source for slugs, so rather than seeing all slugs as bad, they do benefit the gardener by helping break down old plant life. In the absence of leaves, slugs will go for the next best thing, be that cabbages, lettuces or prize hostas. Providing alternative food for them ensures that both slugs and hedgehogs get fed while your vegetable beds and herbaceous borders are (hopefully) left alone.
Five ways to encourage hedgehogs into the garden
Hugh Warwick's top tips include:
1 Do less gardening. Yes, really. Leave wild patches, plant hedges and, if you have the space (and you dare), leave patches of brambles to grow freely.
2 Make sure hedgehogs can get in. Hedges are the best perimeters for hedgehogs and all kinds of wildlife. Failing that, leave small openings in fences and boundaries.
3 Provide food and water, either in the form of specially made hedgehog food (try Spike's World) or by creating the right habitat for its insect-rich diet to thrive. And do not feed them bread and milk. Visit the British Hedgehog Preservation Society's website for more details.
4 Provide shelter. Compost heaps, specially-made hedgehog homes or even just a pile of logs or twigs are all sanctuary for hedgehogs.
5 Prevent injury. Check that fruit and sports nets are not too close to the ground, so hedgehogs won't get entangled in them. Check bonfires before you light them. And provide escape routes from deep water.
Save the hedgehog, save the world
For more details, read Warwick's book or visit hedgehogstreet.org/ to see what you can do to help one of the cutest and most iconic examples of British wildlife. As Warwick says, "If you are making a hedgehog-friendly garden, you are making a wildlife-friendly garden."
• Hugh Warwick's A Prickly Affair: My Life With Hedgehogs is published in paperback by Penguin at £9.99. To order a copy for £7.99, including free UK mainland p&p, go to theguardian.com/bookshop or call 0330 333 6846.