When two different species of animals are together in the same space, it's called an interspecies relationship. This can be a positive thing, because it's often beneficial for both parties.
The interspecies relationship between the animals and the humans was a positive one.
The interspecies relationship between the animals and the aliens was a negative one.
adjective
arising or occurring between species
Synonyms:
1
Interspecies fertility or hybridization.
2
Interspecies traumatic insemination.
3
Implications for interspecies communication.
4
Interspecies friendship and animal friendship.
5
Other evidence of interspecies sexual activity.
6
They rely on machine translation for interspecies communication.
7
This competition is the main source of interspecies conflict.
8
Once there they put forward the idea of an interspecies union.