Mob Spawning Improvements

Currently, mob spawning is often very general and a little odd. I think that the spawning should change a bit. Some examples of these improvements could be making silverfish spawn under wet areas and in lush caves. Cows, sheep, pigs and chickens could all spawn in flat open areas or places populated by humans. Foxes should spawn in dark, shady areas in a cave or under a group of trees at a high Y level. Wolves should spawn wherever their prey spawns, so should foxes. However, this should be less common. These changes would make the game make more sense and would make hunting, crossing or looking for a specific mob more interesting.