The relationships between two or more creatures are sometimes so well-designed and complex that there is no conceivable way that they could have evolved. Sacculina carcini is a microscopic crustacean that begins life as a free-swimming larva. The female first seeks out a crab for a host then she searches for a tiny hole in the crab's leg joint. Finding one, she inserts a hollow tube through the hole and squirts a few cells that are herself into the crab, leaving most of her body behind. As she grows as a large bulge on the underside of the crab, she is also sending tendrils throughout the crab's body.
When Sacculina is ready to mate, she offers one or two pinhole openings to any available male. If a male finds her, it molts off most of itself, enters the tiny hole and fuses with the female. There, they continuously fertilize eggs, producing thousands of new larvae every two weeks. At this point, Sacculina is in complete control of the crab, which is now unable to produce, grow or do anything other than eat. The crab even grooms its reproductive pouch that now scatters Sacculina larvae. Most amazingly, infected male crabs grow female features as well as female behaviors to help scatter Sacculina larvae even more effectively.
The complexity of this relationship surely requires a Creator that is much greater than any crustacean.