Peanut Beetle Culture Care Guide - Printable PDF
If you're interested in peanut beetle larvae as feeders and looking for a simple peanut beetle culture care guide, you're in the right place!
Peanut beetles are so overlooked in the fish, reptile, and amphibian hobbies. I'm always surprised by how many people aren't aware of these incredibly easy to care for and healthy feeders. Peanut beetle larvae are a good mealworm alternative and a peanut beetle colony can sustain itself for many years.
Starting a peanut beetle culture is super simple, and here's why (and how).
What are Peanut Beetles?
Peanut beetles (Ulomoides dermestoides) are small, flightless insects native to Asia. They have a hard shell and are dark brown to black in color.
They reproduce quickly with very little oversight, thrive in low humidity, and do well in room temperature. The peanuts are their home (and their food!) and simple rolled oats can be used as their substrate.
Peanut beetles produce soft-bodied larvae that are like tiny mealworms. They are super easy to care for, reproduce quickly, and simple to harvest. These larvae can be used as feeders for many species of small reptiles and amphibians, invertebrates and arachnids, birds, and fish. Peanut beetle larvae can be fed at any size, so they're very versatile. Just grab the size you need!
What can you feed with peanut beetle larvae?
🐸Poison dart frogs and other small frogs
🐟Betta fish and other small fish
🦎Crested geckos, mourning geckos and other small geckos
🥚Baby chameleons
🦗Mantises
🕷️Jumping spiders and tarantula spiderlings
Why use peanut beetle larvae as feeders?
Peanut beetle larvae are incredibly nutritious (~55% protein and 18% fat) Source.
- Easy to care for and fast reproduction
- Constant supply of food ready to go as they produce larvae.
- Saves money - no need to repurchase feeders if the colony is healthy
- Don’t require much space at all. Some people even use deli cups for their small cultures!
- Odorless! Bc we all deal with enough stinky stuff already 🥲 (2026 edit to add that there is a kind of malty oatmeal smell to the colony because of the peanuts and oats, but it's not a bad smell!)
- Safe and highly nutritious
- Flightless and biteless!
How to set up a peanut beetle culture
Shopping list:
- Habitat (minimum 2oz plastic container with ventilated lid)
- Raw, unsalted, in-shell peanuts free from pesticides or additives
- Old fashioned rolled oats, preferably organic
- Beetle starter culture
Habitat
You will need a ventilated container. I like clear containers so I can easily check activity levels without disturbing the colony. Many people repurpose old plastic reusable food storage containers and drill tiny holes in the lid. I recommend a minimum of 2oz deli cup size to start, but go bigger if you need a lot of larvae. I keep most of mine in multiple shoebox sized plastic bins.
Substrate
Plain, old fashioned rolled oats or oat bran, plus raw unsalted in-shell peanuts (you can buy the ones for squirrels in big bags or even from a grocery store - I find the "baseball" peanuts work great). Aim for .5" to 1" of oats plus peanuts on top.
💡Tip: I have found that filling the container 1/3 with oats, then the rest with peanuts (leaving a gap for air at the top) is the perfect amount.
How to maintain your colony
Temperature and Humidity
They like room temp but a little warmer is ok. Somewhere between 70-80°F seems to be the sweet spot for me - above 85°F isn’t recommended. Keep humidity LOW or else the peanuts and oats will mold.
Feeding the Colony
The beetles eat the peanuts and the grain bedding (oats/bran). Once the bedding looks like fine dust ("frass"), simply sprinkle in a few more handfuls of oats and add a few more unsalted peanuts. Crack some open too!
If you want to, you can add a tiny slice of raw potato or carrot (some people use apples). I don’t do this often, sometimes not for months. You don’t want to introduce humidity and cause the peanuts to mold - it will kill your colony. It is safer to not add anything at all, but some people prefer to.
💡Tip: You can gut load the larvae by separating out the ones you’d like to use as feeders into an empty container and provide those with vegetables to eat on for a few days first.
Cleaning
Frass (the waste created by the colony) will collect in and under the oats at the bottom of the container. Any adult beetles that have reached the end of their life cycle will be in the frass, too. Remove any deceased beetles periodically to keep the colony healthy.
💡Tip: The frass created by the colony often contains small eggs and larvae that are impossible to see, so I never throw it out. If I feel there’s too much frass and want to refresh the substrate, I scoop some out and add to a new container with fresh oats/peanuts and some healthy adults to start a second colony.
Growing from Culture to Colony
Once you start noticing the peanut shells becoming bare very quickly, lots of adults in big groups, and larvae of all sizes/stages within the frass looking cluttered - it’s probably time to size up the enclosure, or even split into two colonies!
When it’s time to upgrade, you can use tupperware/plastic shoebox storage bins with vent holes added (think: larger versions of their starter home!) Don’t go too large though - you want the adults to be able to find each other.
How to harvest peanut beetle larvae
Shake the container a bit to reveal the larvae near the bottom, and use tongs/forceps to grab them individually. You can also sift the oats/frass if you have a larger amount.
Here's how one of my lovely customers does it:
Printable peanut beetle culture care guide for easy reference
Here's how I cultivate my peanut beetle colonies for their tasty tasty larvae in a quick reference sheet you can print out. No email or signup required.
⬇️ PEANUT BEETLE CARE GUIDE HERE IN PRINTABLE PDF FORMAT
Start your own peanut beetle colony
Peanut Beetle Starter Culture with Habitat
Full starter pack with habitat and larvae ready to feed.
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