Why do remora fish attach themselves to sharks?

Answer: To get free rides and scraps from the shark's meals

To get free rides and scraps from the shark's meals ✓ — A remora's suction disc lets it ride along without swimming, saving energy and reaching new feeding grounds. It snacks on scraps from the shark's meals, and smaller remoras also pick parasites off the shark's skin.

To clean leftover food from the shark's teeth — Remoras cling to the shark's body and belly, not inside its mouth. Tooth cleaning is a job some small fish and shrimp do for other animals; remoras stay outside, where they can grab scraps.

To suck the shark's blood for food — Remoras don't drink blood; their disc grips by suction and doesn't pierce the skin. They eat scraps, small prey and skin parasites instead.