Leeches have a reputation as bloodthirsty pests that latch onto humans and animals that dare to enter their watery domain, but not all leeches drink blood. Many types of leeches, including ribbon leeches or bait leeches (Nephelopsis obscura), are scavengers at least part of the time. They feed on debris that collects in the bottom of ponds, lakes and slow-moving waterways. Ribbon leeches also are predatory and eat small invertebrates when they can catch them, using their sharp teeth to bite off bits of flesh.
Ribbon leeches will eat small insects that land in the water and die. Feed them a variety of foods such as crickets, grasshoppers, caterpillars, small beetles and mealworms. Since the leeches may have trouble catching and eating live insects, put some bugs in a plastic bag and place them in the freezer for 10 to 15 minutes to kill them before giving them to your leeches. You may be able to buy some or all of these insects at your local pet store or from online suppliers.
A Variety of Invertebrates
It’s common for ribbon leeches to eat various kinds of invertebrates, and most of these you should be able to buy, raise on your own or find during good weather. Try giving your leeches aquatic snails, earthworms or small crustaceans. Since crayfish eat leeches, be careful about feeding your leeches anything large enough to eat them instead of the other way around. Leeches don’t need to eat every day and should do fine if you give them a couple of snails every week or so.
Other Foods Leeches Eat
Ribbon leeches spend at least part of their time scavenging for and consuming rotting bits of fish and other animal matter, but in captivity it’s usually not a good idea to give them decaying food, since it can foul the water. Amphibian eggs, such as those laid by frogs and salamanders, are a good option for ribbon leeches. You may have trouble buying these, but you might find them in ponds and creeks in the spring.
How Much to Feed
Leeches can only eat so much, and if you overfeed your ribbon leeches, some of the food will go to waste. Wasted food ends up tainting the water, creating an unhealthy environment. Exactly how much they need depends on how big your leeches are, how often you feed them and how many you have. If your leeches don't eat all their food and it spoils, feed them less, but if they clean it all up quickly and seem to be searching for more, increase the amount slightly.
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