Minecraft wiki entry for Survival_in_an_infinite_desert, associated text: A shallow trench, 2 blocks deep, around your house can trap mobs, which you can then kill "by hand". But beware of creepers in the trap. These you must kill quickly. Raise a wall two blocks high, behind the creeper, on the outside of your boundary trench, not the inside, and suffocate the creeper with sand blocks so it doesn't explode. Be careful not to accidentally build the creeper a step up out of your trench on your side.