In a short time, Alros used his aura to paralyze them before subduing the leeches easily. After which he quickly put them inside the lair he prepared for them. Unfortunately, there is no specialized lair for leeches, much to his chagrin.
Thankfully, there are freshwater lair, which copied such habitat completely. After consulting the system space, he soon find out the reason for it.
While habitat lair could have more diverse population, it would be a general type, meaning it would not have the necessities for certain species, while the species lair would not be as diverse, but at least offer the necessities, or at least make it easier for certain species to grow.
It is also the reason why he can put the 10 Black Poison Berry Trees in the habitat, as it make plants that benefit ant species took less space, on the account the lair made specifically for ants.
