Hi Emily
As you say, it seems there are pros and cons to all your proposed sites. There is some information about hog houses here: https://www.hedgehogstreet.org/help-hedgehogs/hedgehog-homes/
If you have hog in the front garden it’s quite likely that they will get into the back garden, too. I would not use slug pellets at all if there are hedgehogs in the area. Slugs and snails can travel a bit too.
The cats probably won’t bother the hogs, although if you were putting food in the box (which I wouldn’t advise if you wanted it to be used for nesting), there would probably be at least one cat which managed to get in! The birdsong wouldn’t bother the hedgehog either.
Bear in mind that if using natural materials to build a nest they like medium sized leaves, long grasses to help weave it all together, that sort of thing. Although you could always leave a pile of suitable material nearby wherever you decide to place the house.
You might find that you need to try out different places to see which works best. But I wouldn’t keep moving the box too often. Sometimes with hogs they won’t use a box until it has become part of the scenery – although sometimes a hog moves in almost immediately.
But I think you are going to have to make the decision yourself. It needs to be somewhere convenient for you as well as the hogs.
Good luck. I hope wherever you choose you get a tenant soon.
