Check the relationship first
In the Zoopedia, look separately at Thriving relationships and Neutral relationships. A shared biome or housing type is not enough to establish compatibility.
For example, the Toco Toucan has no compatible species listed under Thriving relationships, but Golden Lion Tamarin appears under Neutral relationships. That is a neutral combination, not a Thriving bonus, and the empty Thriving list does not mean the toucan has no possible cohabitants.
Preview the group’s housing needs
- Check the other species’ needs as well as its relationship with the first.
- Combine their space, terrain, temperature, food, water, enrichment, shelter and barrier requirements.
- In a built habitat, open Animals → Pin Species.
- Use Add to Selection, then Confirm Selection to see the selected species’ combined requirements.
- Build for the whole group rather than the minimum needs of the first species.
Flying animals need roof netting and enough Flyable Area. Aquatic combinations also need compatible salinity and water temperature.
Recheck social groups and access
Each species still has its own group-size and sex-ratio requirements. Young animals becoming adults can create Outsiders, and too many individuals of the same species can lead to fighting.
Check Social, Environment and Enrichment in each animal’s Info Panel after moving it in, along with its accessible space. Predation is also a possible cause of death, so do not place predator and prey together on appearance alone.