Do pest repellent work for mice

How do I fill a hole in the living room?

First, let's make sure there's no radiator valve down there. If I had to guess, that's a hole from an old radiator, or it was made as an access for repair work. If you see a pipe down there but not a valve, you can probably safely fill it. File a picture away if there is a whistle would be good too.

User35 has solid advice if you just want to plug the hole up. Foam plus steel wool. But your floor looks like concrete, at least from the top. I would push the cavity full of newspapers to put new concrete in the hole. Mortar would work; Concrete with small aggregates would be better. I wouldn't worry about reinforcement or anything like that. It's a small hole and should connect nicely on its own.

That is, assuming it's not as huge a void as you sound like it down there. If you can stick a tape measure in the hole and it stops after a foot or so, whatever. If it goes like three feet, you might want to ask yourself if this is normal for your type of foundation.

That would be normal for a crawlspace, but very alarming if it is a disk. It's not uncommon for the earth to subside to a foot under a slab. In addition, you should take a close look at what's going on. There's also the possibility that this hole was made just for viewing or as a core sample.

MOON

The depth is not 3 feet. I think it's about 50 cm or 1.5 feet. I'll try to measure it.