Monsters spawning in a well lit home

[Tabulius]

Never had this happen before, but I randomly started getting mobs spawning on the second floor of my house after I enclosed it. I use the same amount of light that I normally do and I'm pretty sure It should be protected, the room is a 9x9 interior with torches on either side. It's made the game extremely annoying as they've started spawning even during daylight making my house and all my stuff unsafe.  Am I doing something wrong?

Edited August 27, 2025 by Tabulius

[xXx_Ape_xXx]

Torches do not emit enough light to keep a room of that size safe from spawns. The entire section along each wall, including the corners, are too dark to prevent spawns. In this particular case where you have a shiver spawned, they require a lightlevel of 7 or lower to spawn. The lightlevel along your walls are as low as 3-4.

 

You can check the lightlevel by turning on the extended debug overlay, by pressing ctrl+F3

Then you look for the values on the far right side, following Block V: at the end in the marked area in my picture:

As you can see in the bottom picture, the values are way bellow the values needed to prevent spawns of any unfriendly mobs.

And yes, I recreated your room 

 

You can keep this size room safe by either placing more torches along the walls, or by placing a lantern in each end of your room, where you now have the torches

Hope that helps!

Edited August 27, 2025 by xXx_Ape_xXx

[Tabulius]

My god, thanks man, props to you for going way overboard in explaining this! I ended up doing what you said and lowered the torch and now it's safe. I also found out that mobs were spawning during the day cause I left my cellar open.

[CastIronFabric]

This is a feature I would like to see 'fixed'. By 'fixed' I mean to my liking.

Because really love the lighting affects in this game for a dimly lit environment filled with candles and torchers instead of lanterns.

That said I play on Explorer mode so its not a big deal, its just now and again my armor stands move because the bugs in my house move them by bumping into them.

 

 

[Eupaf Ternine]

Gotta agree. At least some kind of slider or spawn-proof in rooms