Here's why:
* Orcas are apex predators: Orcas are at the top of the food chain, meaning they have few natural predators.
* Size and strength: Orcas are large and powerful, capable of taking down much larger prey like whales.
* Intelligence and hunting skills: Orcas are highly intelligent and coordinated hunters, making them difficult prey for any predator.
While some shark species are large and powerful, like great white sharks, they are not known to prey on orcas. In fact, orcas have been known to hunt and kill great white sharks in some areas.