Enrichment would be a new comfort requirement inspired by Frontier's Planet Zoo game and the way animal enrichment works in it.
Each animal would require an enrichment item in their habitat as part of their comfort needs. Examples of such items in Planet Zoo range from toy balls, tyres, and rubbing pads to mud baths and specialized feeders. Certain types of items would be more desirable for specific animal families and cater to their behavioral and anatomical traits.
Animals interacting with these items would introduce new behaviors to the game through a range of unique animations tied to the respective enrichment items. This would further help the animals in Evolution feel alive and real by allowing them to exhibit more naturalistic actions beyond primary activities such as feeding, drinking, and sleeping.
As it stands, social interactions remain the only major behavior animals in the Evolution series partake in when they are content that does not serve to fill any of their currently implemented status bars. Enrichment activities would be a great way to expand the life simulation aspect of the game and offer more variety in the experience of viewing species thrive in their habitats.
Attached is a screenshot from one of the Planet Zoo trailers.