To know what millipedes look like, here are some pictures of millipedes:
You may ask, "do koi fishes eat those millipedes or is it safe for koi fishes to feed them with millipedes?"
Koi may eat those millipedes but to be safe, you should not feed your koi fishes with millipedes. Millipedes secretes harmful or poisonous substances such as benzoquinones, alkaloids, phenols, terpenoids, and/or hydrogen cyanide, among many others. Some of these substances are corrosive and can burn the exoskeleton of ants and other insect predators, and the skin and eyes of larger predators.
So better not to try feeding your beloved koi with those millipedes. If you want to experiment feeding them with millipedes, then let us know in the comment below the condition of your koi fishes after feeding them.
Have you tried feeding your koi's with millipedes? Let us know in the comment below the condition of your Koi fish after feeding with millipede.