Summary:

When trying to breed axolotl, there are no heart particles and the baby axolotl does not spawn.

Steps to reproduce:

1. Spawn two axolotls
2. Try to feed both of them tropical fish

Observed Results:

The axolotls get no hearts above their heads and the player starts to eat the fish.

Expected results:

The axolotls will get the heart particles and breed. The baby axolotl will spawn.