[B19 0.19.2009] Dog's and Cat's won't hunt other animals for food.

[viperwasp]

What the circumstances were.
I updated this Bug as after further testing I also found that dogs won't hunt either.

Version B19 [0.19.2009] on Steam, no mods, new game.  Cat's won't hunt. Also Labrador's and Husky's do not hunt Cat/Raccoons/Rats either? Requires further testing to see if other animals are effected but devs may have to figure out what is wrong.

What happened.
Spawned many cats, and many rats. No animal zones, waited for cat to get hungry. Cat's still won't hunt. Has been a bug since at least B18.

What you expected to happen.
I expect cats to at least hunt animals smaller than it. For example rats at least. In previous versions of Rimworld various animals
hunt smaller animals. I think both Dog's and Cats hunted rats, things like squirrels. This no longer happens. A developer or someone else can maybe go back to A15/A16 before this bug started and figure out what animals are supposed to hunt what other animals.

Steps we can follow to make the bug appear on our machine.
1. Start new game.
2. Spawn Cats. (Can also test dog's etc.)
3. Spawn Rats. (Or other small animals)
4. Fast forward time and observe cat behavior.

See these attached links for the same bug.
1. https://ludeon.com/forums/index.php?topic=36668.msg378273#msg378273
2. https://ludeon.com/forums/index.php?topic=39279.msg400132#msg400132

Thanks!

[viperwasp]

Here is a following quote from a user named Mehni. This could be the reason why this bug exists.

Expected behaviour:

Pet and wild cats should hunt small rodents such as rats/squirrels/hares.

What actually happens:

Cats rather starve themselves to death rather than lift a paw. While this is typical cat behaviour if I were to believe Garfield, I do believe this is wrong.

How to verify:

Enable dev mode, Draw Prey Info.

What I believe to be the underlying issue:

// RimWorld.FoodUtility.IsAcceptablePreyFor directly checks for ageTracker.CurLifeStage.bodySizeFactor of predator and prey, rather than multiplies that against the body size.