This is known as a native American style fish trap and it works so simply that it’s brilliant! First, you need to collect a good number of sticks of varying sizes. Once you’ve got plenty you find a good place in the water with a shore or rock for the 4th wall. Then you basically put down the sticks into a large “M” shape. You leave a small gap in the middle of the “M” along with some bait in the center to draw the fish in. Once they’re inside they stay trapped because they’ll consistently to escape via the pockets in the corners instead of ever realizing they need to go out the way they came in!