I'm pretty sure this is more related to modding and map creation than actual Minecraft, but I need support nonetheless.

I am creating a cool (and secret) project in Minecraft right now, and I need to place mob spawners in important places. I tried using LolEditor to give myself spawners and then placed them, but they made pigs. Not exactly terrifying. I then tried using NBTedit to make spawners, but those spawners dont make anything, and don't even spark flames! Does anyone know of a program that will let me place operating spawners in my maps without overhauling my maps? (i.e. DungeonMapper, where it remakes a large portion of your map but does indeed install working spawners.)

Any help is greatly appreciated!

~Mr. 8bit Ghost

(PS: Does a mob spawner not work when being placed on bedrock/adamantium/chucknorris? Because that is what it is on, and i'm not sure if that stops it from working or not...)