Put the summary of the bug you're having here

What I expected to happen was...:
Fully lit spider spawner should no longer spawn mobs. Fully lit zombie spawners should not spawn any mobs either.

What actually happened was...:
Fully lit zombie dungeons spawn in riderless chicken jockey. The chickens attack you and sound like the baby zombies. Chicken and feathers are dropped when you kill it. Also, the chickens are sometimes spawning in taking damage and the drops shoot up from the ground. It only does this about 8 times then stops.

Fully lit spider dungeons are spawning skeletons that don't do anything. They do not interact with the world at all. you can hit them once but after that, nothing happens. They still take up space. you can push against them. They spawn in solid blocks and don't take damage. If you dig the block out under them they don't fall. Unlike the zombie spawner, this doesn't seem to stop.

Steps to Reproduce:
1. Find a zombie or spider dungeon
2. Light it up to stop spawning
3. Watch