thank you so much for the advice. Just this evening I carefully and quietly checked the hedgehog house as I hadn’t seen the hog for a few days on the trail camera. The hog house was empty and i took the opportunity to clean it out (there was quite a bit of hog poo in there!). On cleaning I also found probably about 20 ticks in there :-S
Some were dead, whilst quite a few others where crawling! I totally emptied it out, and cleaned up as best as I could. Now that I have read these replies I will go at it again tomorrow (given the hog has not returned overnight). I will clean both the hog house and the feeding box (situated in totally different parts of the garden) with both boiling water and I will make up that essential oil spray also and spritz that in there too. The poor hog – I wish I had checked the hoghouse sooner, but since I bought it about 2 months ago the resident had moved in pretty sharpish, and so I thought best to leave it well alone and leave the hog in peace to get on with life 🙁
I hope that the hog returns – it might have been too many ticks for him/her to deal with. Will update if that is ok. Many thanks for both your help.