Hi Matthew
I think you need to make contact with a local hedgehog carer. You can find your local one by ringing the BHPS on 01584 890801. If you think it fell in, it may not be able to get out. You can discuss it properly with them. It’s difficult giving advice on here, when we don’t know all the facts.
In the long term making a hole in the boundaries would be a good way to go, but ideally encourage all your neighbours to do likewise, so that the hedgehogs can come and go as they like.
Meanwhile leave water out 24 hours a day. It may be drinking when you aren’t looking!
