Whenever a sheep is set on fire, it won't run into for example a river, but will instead stand right in front of the water. (Also, wolves ignore being on fire, but that could be intended)

What I expected to happen was...:
When the sheep is set on fire, it will run into the water and extinguish the fire.

What actually happened was...:
The sheep ran to the river, but stood right in front of it instead of jumping into the water.

Steps to Reproduce:
1. Spawn a sheep next to a river and wait a short amount of time (otherwise it seems not to respond to being on fire). Also don't spawn it in fire already, otherwise it also doesn't respond to being on fire.
2. Set it on fire with for example flint and steel.
3. See how it runs right in front of the river, but doesn't want to go into the water.