There is a great deal of information on the internet about wild hedgehogs generally and feeding them in particular, but one of the main things NOT to feed them is milk. Hedgehogs are lactose intolerant and feeding them milk harms them.
Hedgehogs are basically meat eaters, specifically insectivores. They also eat slugs, snails, worms and carrion. They do not normally eat fruit or vedge. They will eat meal worms but there is evidence that their consumption can cause metabolic bone disease. There is also plenty of information about this on the internet, but it is unwise to experiment with feeding as the results of the experiment may be hard to detect. We feed hedgehogs minced beef and cat biscuits. A ‘value’ pack of mince costs about £2.25 per lb (£5 per kilo). We feed the hedgehogs in 2 separate places to stop the early bird eating all the worms! There are currently at least 4 different hedgehogs who drop in every night. An egg-cup full of mince weighs about an ounce. I roll them into balls and freeze them. I put half a defrosted mince ball in each popin (food station) i.e. a quarter ounce of steak tartar costing 7p, with half an ounce of cat biscuits in each costing approx 3p. Some people suggest ‘meaty’ tinned cat or dog food. Our dog refused to eat the stuff and from experience hedgehogs will only eat it if there is nothing else. (Nor do they eat any of the muck labelled ‘Hedgehog Food’ that I have tried.) Dry ‘whole food’ pet biscuits are better for hedgehogs’ and your pets’ teeth. In any case, once opened tinned dog and cat food goes off quickly. Bottom line is feeding hedgehogs minced beef is cheaper and better for them than tinned food.
To ensure you are feeding hedgehogs, rather than cats and other opportunists, you need a simple ‘shelter’ in which to put the food. There are numerous examples on the internet. One simple, sturdy and cheap version is shown on my POPINA page.
The other very simple thing you can provide is safe and easy access to water. I have filmed hedgehogs ‘drinking’ for more than a minute in the recent hot weather. We have no pond or other natural water in our garden and I am not aware of any nearby. The further hedgehogs have to roam for water (or food) the greater the risk they face of being run over or predated. If you have hedgehogs coming to your garden it makes sense to provide them with water. Similarly, if you have water in your garden (pond, pool etc) try and ensure safe means of escape should any over inquisitive hedgehog tumble in. They can swim, but cannot scale a sheer sided pool. Open drains and netting (garden or tennis) are also hazardous to hedgehogs. Being inquisitive by nature but possessed of poor eyesight, hedgehogs are accident prone. Please also urge your neighbours to take care strimming! Strimmers can cause terrible injuries or a slow death to the humble urchin. Similarly bonfires should be checked for lurking hedgehogs before lighting; a hedgehog sees a bonfire or compost heap as ideal daytime shelter. I tip my bonfire onto a tarpaulin before rebuilding it and firing it. And mind how you go with that fork! Slug pellets are another no-no. If you prefer prize dahlias to live, healthy hedgehogs, (not to mention the birds), scatter the wretched things around. ‘Covering’ them or putting them under a tin is no deterrent to hedgehogs who are masters at extracting food from under an upturned dish – a skill which seems to be entirely beyond most cats.
For more information or advice here are some websites. There are others!