Zombies spawning indoors

[Thabows]

Hi I'm having some weird zombie spawns lately. I'm using the FTB Direwolf20 pack version 1.0.18. I've been playing for a few days now and for some weird reason I have zombies spawning in my house. It is well lit so it's not a light level issue (I'm using direwolf's 9X9 style of house). And today the weirdest thing happend, I just got indoors and I notice there's a zombie in my house. I'm thinking "darnit again?" and to make it even worse (and weirder), as I start killing the zombie MORE spawn in front of me! There were a total of 5 maybe 6 zombies in the end but had no trouble killing them. Now my question is: Is this intended by some mod I'm not aware of? Or is it because there is an eerie biome like 50 blocks from my house?

Ty for reading and hopefully a sollution

 

[Celestialphoenix]

Vanilla has some gimmick with zombies spawning zombies.

But the eerie biome probably makes it worse.​

 

[YX33A]

How many villagers nearby? Get enough nearby and with enough of the resulting village light up, this is unavoidable. A room with no lights accesable only via a "mob proof" floor(read: fences over a deep enough pit to break pathfinding, ideally with carpets over the fences since that looks nicer) would force this to be a hilariously effective mob spawner IMO.

 

[Thabows]

Vanilla has some gimmick with zombies spawning zombies.

Oh I didn't know that, but now with you saying that I have had that before. Like you hit a zombie and it sort of duplicates, that is sort of "acceptable" but the weird 5-6 zombies spawning that was just over the top :S.

How many villagers nearby?

There are no villagers nearby, maybe some more than 200 blocks away but that should be well out of range. And that mob spawner idea shouldn't be too bad if you don't like normal mob spawners or mod based spawners.

 

[YX33A]

Hm, not sure then. Does kinda sound like you have a spawner near by, then, or a part of your base is actually not fully lit up. Which can be hard to tell without using NEI's "safe lighting" checker.