. . . Jupiter's moon Titan has long been thought to be a likely location to find life forms. Titan is covered in ice and has an internal heat source. The torsion of a changing gravitational pull from orbiting that massive planet generates enough heat within the moon that it is thought to hold a vast liquid ocean underneath the ice. If there's life within comets then Titan is guaranteed to have been infected. The stable environment it provides would allow enough time for multicellular life to evolve. . .
Now imagine if intelligent life evolved beneath the crust. What would it do to their world/universe view to be contacted from outside? Outside might not even be a concept to them. Good stuff man.