You don't, they'll choose. Plenty of cover, slugs, and leaf litter. Worthy

We've got all that, but still no hedgehogs for twenty years, Worthy :-( I always assumed that they couldn't climb up our 1 in 1 hill.

We had Hedgehogs galore until all the fences went up with concrete thingies at the base in most adjacent gardens. Then they are forced onto busy streets and squashed or predated by increasing urban foxes. At one time three of them hibernated in my border in beautifully constructed nests in the border edge. Lined with leaves and expertly roofed over. They had a maternity unit too and all the babes came out to play in the evenings. We live 7 minutes walk from town centre. We are too tidy, and too keen, in small town gardens, to block off every chink where something ground hugging might travel about a bit, as just one garden not enough.