Put this in deep water, load it up with 5 of any type of bait, and wait... Come back and check the trap by punching it occasionally. It may be days before an animal will wander in! You just better hope they don't wander back out with your bait.
The Lobster Trap is an unsplicable non-solid foreground block which was added along with the Gone Crabby! update on March 3,2016.
To use a Lobster Trap, place five of any bait inside the trap. It can take anywhere between 1-2 days before the trap is ready, the more Water Buckets placed on and above the Lobster Trap, the higher the lb. (max of 3 Water Bucket placed above). However if left alone long enough after it is ready, "The bait was eaten" text will appear in red when you punch it and no crab will be obtained. The location of where the trap is placed in the world does not matter, as long as it has its necessary depth. Punching it will give any of the following:
The given sizes above indicate what is the max possible size you can obtain from the trap. For example, a Lobster Trap with 0 depth and baited with 5 Wiggly Worm will only yield a size from 1lb. to 5lb.