We have 4 different biomes that the pets can be in.
We initially had it where players could move the pets to different biomes by entering their current biome and then having them run to the next biome. However, that takes a lot of time to cycle through for the player and was a bit weird because that might have forced pets to run across certain obstacles. Additionally, we did not want there to be 2 pets sharing a biomes.
We decided to instead let the players do the swap in the map area where you select the biomes. This is significantly faster. Players will also have a clearer indication on which biomes are full/ why they cannot put a pet in the biome.
There will still need to be some work done on letting players know that the map room is where the player can change biomes and how to actually do the change. Currently, the player simply holds on the icon for a bit to move it. Whether it will stay that way remains to be seen. It is not something that is obvious at a glance.