Troubleshooting Fish That Won't Flock

Check the Obvious First

If your fish look identical to vanilla behavior, confirm the mod is actually affecting them. Boids replaces flocking fish behavior, so fish types that do not normally school may not show obvious changes. Start by testing with a fish you know schools in vanilla.

Common Causes and Fixes

1. Too few fish. Cohesion needs neighbors. A single fish or a pair has nothing meaningful to align with, so add more of the same type.

2. Tank too large. In a huge ocean or a giant pool, fish rarely enter each other's perception range, so the flock never forms. Build a smaller enclosure to verify the behavior works, then expand.

3. Obstacles everywhere. Every block between fish reduces effective neighbor detection. Clear a central open area.

4. Mixed species confusion. Different fish may have different movement characteristics; keep a school single-species while testing.

5. Conflicting mods. Other mods that overhaul fish AI or mob behavior can override or fight the boids rules. Test in a clean setup if nothing else works.

Verifying It Works

Drop several identical schooling fish into a small, empty pool and watch. If they begin matching headings and clustering, the mod is functioning and the problem is your tank design, not the mod.