Cats despawn in a village in 2 minutes

In a flat village with the player standing on the same level as the village of 5 villagers and beds, I would expect 5 cats to spawn between 32-64 blocks from the player.  What happens is one cat spawns, 40 seconds or so another one does, then in at the next 40 second mark the first cat despawns and another one spawns.  So there are only ever 2 cats.  The despawn time of 2 minutes holds true for "egg" spawned cats in any circumstance.