In Survival Mode Hostile Mobs Spawn Eggs are Consumed in Peaceful Difficulty

Steps to Reproduce

1. In Survival Mode Get some Monster Spawn Egg(Ex:Zombie)
2.After that put on Peaceful Difficulty
3. And in this difficulty spawn this Egg Spawn somewhere. As you can see the mob does not spawn because it is in Peaceful difficulty But the Egg Spawn it spends every time we try to spawn the mob