Bubzer
Terrarian
As the title suggest, it might be nice of have the option to reduce critter spawns, or eliminate them altogether, while not impacting normal mob spawns. The item itself could be a phonograph, or perhaps a mint plant (some animals, like Deer, don't like strong scented plants). This could be useful for builders who want to suppress critters, but not mobs. It could also maximize mob spawning in an area, via preventing critters from taking up a slot from the maximum number of active spawns.
Anyways, it just a thought.
Anyways, it just a thought.