building a mob trap for spiders is a little bit different because they won't fall down that drowning hole the blocks were going to need for this trap are two buckets of water some sand some cactus plenty of ladders cobblestone dirt torches glass and a sign start by blocking off any exits so your spiders can't escape and I'm going to replace the cobblestone around the spawner with dirt and put torches on that dirt to incapacitate the spawner put the torch back on and the same thing on this side so now I just need to dig down two blocks so I can go beneath the spawner dig out the entire room be sure to leave those dirt blocks with the torches on them so the spawner is still incapacitated all right so finally I have a room that's seven blocks wide also seven blocks long and two blocks underneath the spawner I need it to be 12 blocks long so I'm gonna count my way across seven dig into the wall 8 9 10 11 and 12 I'll do the same thing on the other side 8 9 10 11 and 12 now just dig out all this stone I'm going to place glass on this back spot here eight blocks away from your back wall and leave a small space for you to get through now it's time to build an internal spring by digging three blocks back and then those last two blocks down pull out your two water buckets place them in opposite corners and you've got an eternal spring pull water from it and start lining this back wall with water this is what will push your spiders into the trap just make sure you have one more bucket of water before you head back in your back room here dig down one layer right here where the water ends this will be your collection trough one block behind that dig out every other block and replace it with sand and place cactus on top of that sand these cactus are what's going to kill the spiders so back in your spawning room you're going to want to close up your eternal spring and get rid of these torches the ones on the wall first and then you can use your shovel to quickly get rid of the dirt and get out of here before the spider spawn not quick enough well there it is the water pushes that spider into the cactus and that hurts him until he dies you can see drop string right in that collection trough just place your last bucket of water in that corner there and it'll push your string to a single collecting point and that's your spring collection spot so to get out just dig your way straight up and start placing porches and lappers there it is the surface you're going to wanna place a sign so you'll know in the future what this ladder leads to so let's head down and collect some string I got kind of lazy and I didn't dig this out two blocks wide so I can't fall I just have to travel at the latter speed so I'll speed it up a little bit and here we are you can use this mob back to collect all the string you'll ever need