when your playing with zerg, seeing 12zealots walk into your base could mean death for you unless you have alot of sunkens which watses to much precious money. First of all find a canal at the entrance of your base or the expansion depending on the map,build creep up to the canal or build a hatchery there. Start building sunkens in this canal, about 4 to 6 once youve done this build evolution chambers in front of those sunkens, if the canal is the right size you should be able to fit 2 or three perfectly in front of the sunkens, if there is a small gap just build a creep there and turn it into a spore or anothere sunken. If you do thid correctly zealots or zerglings cant touch you, if they attack the evous your sunkens will just wipe em out before they can. if they do eventually get through after a few trys you should have some zerglings and hydras to kill them or more sunkens inside your base. This tactic is also very good against toss comps which wont attack the evous, this tactic works well on bgh

CreepColony's Opinion: Most effective against comps.