Naturally Spawning Axolotls don't go for Glow Squids

The title might be a bit misleading, but I was just wandering around, and saw a little water lake in a cave. In that exact lake, both an axolotl and a glow squid had spawned. They both spawned in the same water body, but the axolotl didn't care. Only after I put MY axolotl, the glow squid was dead. The natural one didn't care.