Open up the garden removing anything stacked or stored that rats can burrow under,timber,plant pots,compost bags,anything. They often go to the nearest food source,so dont throw out any scraps for the birds,& remove any feeders that seed, grain,suet can fall from for now,stored foodstuffs in garage etc,move all & keep your son away from affected areas. Dispose of droppings..uniform torpedo shaped,4-6ml long & use jeyes fluid to wash everything down, the childs playthings too,but dry off well & keep them indoors if pos'. Also block the hole under the fence using solid material,big stones,brick ends,stuff that cant be moved easily,& keep checking no fresh entrances have been made. Does anyone nearby keep chickens? Can be worlds worse for attracting rats.

If it's rats. KILL THEM! You may use mechanical traps or poison bait but KILL THEM! Then you can use the control measures as pajo has mentioned to deter them. Of course with these lethal methods consider well and use common sense in placing them where your children or pets may not be harmed. Ok, now that I am over my histrionics, the best way to find out is to use a LIVE TRAP. Place a suitable bait in the trap, one that you think that both the hedgehog and rat would enjoy, place it in your shed and check it every day. Have patience because rats have newphobia. That is they will avoid any thing new for several days in their territory. Trapped a hedgehog? Release him from the live trap so he can go on his way. If, on the other hand, you have trapped a rat..........well you know what to do.

Do NOT block up all gaps and holes around your garden and do NOT remove stacks of natural materials either because you will immediately stop and/or trap the visiting wildlife such as frogs and your hedgehogs.

These natural habitats are to be encouraged and just deal with the undesirables as and when they arrive - but don't go all gung-ho and remove every scrap of natural habitat or you'll have no wildlife at all.

Using human traps such as the one Eclectic suggests is the best way forward.

'Using human traps'

How big are these rats? You miss one key on the keyboard...(sorry)

I've had a Monarch type trap (under £19 inc P & P from Amazon) in the garden for about a week. I can see that the rats are interested in the food on offer but haven't, yet, gone for it.

We have a very wildlife friendly garden (should that read I'm too lazy to do lots of clearing up?) and a field at the back so, I suppose, getting rats is the price you pay.

This http://www.leptospirosis.org/ looks like a useful site for information on Weils Disease.

Incidentally, whilst agreeing with Lousie1 about the garden, the same is not true for the shed.

I spent a lot of time using silicon sealer to close every possible hole in the shed. All the joins, knot-holes, cable entries, etc.

And I move everything out, about once a year, to make sure no new holes have appeared.

I also place a weight against the door to make sure it is tight up to the doorframe so not even the tiniest mouse can get in.

rats are realy inteligent its not hedgehogs i dont think . rats constantly dribble urine and arnt to fussed wear they go to the loo . i dont think hedgehogs at all sorry . you can get specific rat poisan boxes made for them .

Also, the hehgehog droppings I have seen have been nothing like rat droppings, which are like big mouse droppings ie pellets. So you may well have both.
If I were you i would kill the rats. I wasn't keen on poison but resorted to it when humane traps didn't trap ant rats, only pigeons! And rats breed every six weeks so good to act quickly.
As Louise says, we need to leave our gardens accessible to hedgehogs so blocking off their access is reducing their territory.
When I did it, I placed the poison at one end of a kitchen towel roll holder and taped that end off. I pushed the cardboard tube under some ivy on the ground where I knew birds wouldn't go (or hoped they wouldn't) and within a few days I found a dying one. Then came a decision to put it out of its misery and I quickly dispatched it. Found a dead one too.
It IS a horrible way to kill a living creature but if anyone knows another way, I'd be grateful to know it too.

Thank you for your replys I'll try getting a trap and c what I catch.

Pest control told me that they love chocolate, if you are trying to catch one.

Checking the droppings against both rat and hedgehog poo would be a good idea- pictures available on Google. I'd block up holes in the shed so whatever it is can't get inside, but leave the gap underneath - hedgehogs often hole up under sheds for winter, and you don't want to kill it or drive it away.

Sorry folks if my method seemed radical. Being a country dweller I've been dealing with these loathesome,intelligent,& habitual rodents, + their smaller counterparts all my life. Sometimes one does have to sacrifice the sprat to catch a mackerel. Rats are pa rt of our wildlife sadly,& in great abundance,they are everywhere. Catching them humanely,or otherwise may seem an ideal solution..if we know exactly how many there are,ie have they found a suitable nesting site,cover,protection from the elements,a regular food supply? By taking these away once we ARE aware they have, or are about to set up home,using lateral thinking to outwit them really is the quickest,easiest method. Exposing them. Only within a few metres of their site..other wildlife wont be using it anyway if rats have scented there,same with a burrow under a fence, & it would only be for a short time. Also,as per Electic's advise,when this exposure is taking place,have someone unsentimental,with sharp reflexes,& a sharp spade standing by...or borrow a pals terrier. Quick & humane. If they are visiting rats there will be evidence of a run(a path they strictly keep to,even when disturbed,a well trodden track visible in any earth) & the only reason they will be visiting under cover of darkness is for food.

I'm sorry to offer simplistic advice, Danny, and, of course, it may not be an option, but a good hungry cat or terrier will sort out the difference immediately. We live next door to poultry sheds, dried cat food is always readily available around the place and yet the only rats we ever see are the few half-eaten corpses we are brought as "presents". Maybe someone should start up a "rentaravenousmoggie" service. I rather doubt a hedgehog would actively burrow under a fence, but they do dig themselves very energetically into bags of compost and can squeeze through surprisingly small gaps, so I suppose anything is possible. Hedgehog droppings are very like cat droppings, but smaller, obviously, and almost black and quite moist. Rat droppings are far more like pellets. PLEASE be careful with the poisons.

Ha ha Gattina..praps we can start a service between us?! I had never ever in my life,even on the farms i've lived,come across cats that would eat rat...until that feral kitten i took in,pregnant, reproduced herself x7. She doesnt eat them herself,but her offspring do! At only a few weeks old,& before four of them went to permanent homes,I would have to take myself elsewhere in the garden,& from 'childminding' duty when young mum would return singing that 'look what i've caught' song,as they do,to deposit a half grown maimed rat on the lawn for them to kill. To my initial disgust,as the weeks went by & the rats became bigger & less maimed,I found they'd begun EATING them too! Yuk! They are like no cats I've ever known though. Overly affectionate, were mega advanced at an early age,& are acutely instinctive as adults...Is this a feral trait thats been passed down by a cautious young queen,originally from domesticated stock, who had had to fend for herself for a few months?

Erm, Gattina, hedgehogs definitely will burrow under a fence, or even gnaw through a wooden barrier erected suddenly. Our next door neighbour replaced his back garden wooden gate with one which went down to the ground - that night there was an almighty racket coming from the alleyway into which his and my door opened - when I looked, it was a hedgehog decimating the bottom of the new door so he could get through... and he had a little tunnel under the fence panels between our gardens where he'd cross between gardens.

PS. POISON..Its not just the creature that the bait is put down for that often takes it,also consider what might then take a creature that is alive,but disabled from having poison in its system. Many birds of prey are being killed just over the Welsh border,as have 3 of my daughter's cats over a two year period. Poison is bad news.

OMG Bamboo..that's incredible! (it was'nt that giant Monty Python one called Norman was it? lol) He was obviously t'd off because his habitual route had been blocked. Saw one recently trying unsuccessfully to get through a length of newly erected plastic temporary barrier mesh...so climbed it instead!

Ha ha, yes apparently they climb anything that's blocking their way - it doesn't seem to occur to them to go round even where that's possible. I once saw some footage of one climbing a bit of mesh fencing specifically put in place to be filmed - the fencing panel was 4 feet wide and 5 feet high, with no barrier either side. Yet the hedgehog chose to climb the fence instead of trying to see if it could get through another way...
And when that hedgehog was breaking the gate next door, I thought someone was trying to break in to my house, it was that noisy.

Can imagine Bamboo. They have some strong jaws on them & are determined beggars. Not sure if its that stubborness rather than them not being overburdoned with brains that makes them do such things ???

Pajo, joking apart, we have never seen a half-eaten fully grown adult rat - just young or adolescent, I would guess. Maybe, bearing in mind that all our cats have at one time been fully feral, they are just really good at killing the young ones of any litter that actually manages to get produced. You are absolutely right about the poison being taken up second-hand: hunters round here (illegally) put down what they call "polpette" (strychnine meatballs) to kill small carnivores that would spoil their fun by eating the pheasants they'd like to shoot, and we get warning leaflets through the letterbox about unexplained deaths among pets who come across the carcasses of rabbits and such-like and try eating them. We're supposed to report them to the police, but only after you've had an expensive autopsy done by the local vet. We came across one of our loveliest cats, Sooty, a sweet and dopey long-hair who couldn't have caught a cold, much less a full-grown bunny rabbit, trying to pull a huge carcass through the cat-flap. We panicked and took it off him, quite forcefully, as all the others were crowding around, trying to get a piece of the action. That was very scary, and we took the corpse away and burnt it.
Oh Bamboo, I love your story about the Norman hedgehog. I suppose nothing should surprise me about the behaviour of a determined and rather cross animal. We haven't tried to get any of our hedgehogs through the 11+ yet, but I'd be surprised if any of them managed it: amazing vocal range but deficient in the grey cell department, I think.

Well, you can't have everything I guess, lol!

Well, we like to think we do the best we can for our children.

Thanks to Gattina, Bamboo, Payjo, Danny Brown and even Eclectic. I know this is a very, old, blog, thread and none of you may still be around to read my thanks. I have hedgehogs and at least one rat visiting my garden. This thread discussed all the issues and concerns around the problem of encouraging hedgehogs without encouraging the rats. I have found it helpful and has given me food for thought. Big thanks to you all.