I found another monster spawn, but I dont want to just destroy them, is there a way to make your monster boxes into a fast way to harvest items? any ideas? what do you do with the monster spawns when you find them?
You can set up a drowning box where the mobs get trapped and the items are washed under a block to an area you can recover them.
You can also do similar things with auto turrets by funneling the mobs into a single tunnel that has pressure plates attached to arrow dispensers.
I did a similar thing, I dug a two block deep trench around the Spawner, six block long, the water washes the mobs into a hole over 24 blocks deep, which is a instant death when they land, I just stand at the bottom collecting a consent supply of arrows
and bones and made a rail track down to the pickup.