Here's why:
* Diet: Arctic foxes are opportunistic carnivores and will eat a wide variety of prey, including small mammals like weasels.
* Size: While ermines are smaller than foxes, they are still a suitable size for a fox to hunt and consume.
* Competition: Arctic foxes and ermine weasels live in similar environments and may compete for resources, including food.
It's important to note that while Arctic foxes do eat ermine weasels, it's not their primary food source. They often rely on other prey like lemmings, birds, and fish.