Finding Worms
Worms are the core bait item in Aquaculture 2. You can obtain them by breaking grass and dirt blocks with a shovel — worms drop occasionally. They also come from the 
Worm Farm block, which is the sustainable way to produce them in bulk.
Building a Worm Farm
Craft a Worm Farm using wood and other basic materials (check JEI/REI for the exact recipe in your version). Place it on the ground. The Worm Farm produces worms over time when it has valid conditions — typically it needs to be placed on dirt or grass and may require compost or organic material to function. Once placed, right-click the farm to collect worms as they generate.
Using Worms as Bait
Hold a 
worm and right-click your fishing rod to attach it as bait. This reduces the time between bites and can improve the quality of your catch. Worms are consumed when you catch something, so keep a stack on hand.
Worm Farm Tips
- Place multiple Worm Farms for faster worm production.
- Keep the farm loaded (chunk-loaded or near your base) so it keeps producing.
- Combine worms with hooks for the best fishing results.
- Worms can also be used to breed certain mobs if the mod allows it in your version.