How To Raise

Dermestid Beetles

If you're looking to start your own colony of dermestid beetles, you've come to the right place!

While they are relatively easy to care for, be prepared—their enclosures can develop quite an odor over time. A small, freshly established colony in a 10-gallon aquarium may be manageable indoors at first, but as it grows, the smell will become more noticeable.

Optimal Growing Conditions for Dermestid Beetles

To ensure a thriving dermestid beetle colony, it’s essential to provide the right environmental conditions. These beetles thrive in warm, dark, and dry settings, making it best to house them away from direct sunlight and weather exposure. Since they can fly at temperatures above 80°F, maintaining an optimal range of 75–80°F is ideal.

A well-structured enclosure with proper substrate layers enhances colony health and maximizes population growth. I prepare my colonies using a three-layer substrate system:

1. Bottom Layer: Styrofoam – Dermestid larvae love burrowing into styrofoam, especially when pupating. Over time, as they chew through it, small particles accumulate, which is why I place it at the bottom. In large colonies (such as converted freezers), I use 3–4 layers, creating a 4-inch deep base.

2. Middle Layer: Recycled Paper Pellets – These highly absorbent pellets help dry out specimens and control odor, preventing excessive moisture buildup. A 1-inch layer is typically sufficient.

3. Top Layer: Shredded Aspen Bedding – Aspen is the only safe wood pulp for dermestids, as other woods often contain chemicals or natural insecticides. This layer retains warmth, absorbs oils from specimens, and provides an additional burrowing medium.

Adding a few chunks of styrofoam within the enclosure also gives larvae extra places to hide while pupating.

Watering Your Dermestids

While dermestid beetles obtain most of their moisture from their food, occasional hydration is beneficial. The best method is to place a paper towel over food and mist it lightly once a week at most during warm months. In cooler conditions, watering once every two weeks is sufficient, as they can absorb moisture from the air.

Another option is placing a damp cotton ball inside an upturned lid, ensuring no standing water is present. Since dermestids drown easily, any pooled water should be avoided.

Personally, I do not provide additional water when my beetles have a constant food supply. My colonies are kept in thermoregulated, automatically vented freezers with a steady food source, eliminating the need for extra moisture. However, in previous indoor setups with ducted heating, I found that weekly misting was necessary.

Feeding Your Colony

Dermestid larvae are voracious eaters, consuming up to five times their body weight daily. While adult beetles eat relatively little, larvae prefer meat over organs or skin and will not consume fur or feathers. Therefore, it’s crucial to skin and eviscerate specimens before feeding.

For optimal colony health and odor control, I recommend drying specimens before feeding. Placing them in front of a fan for a couple of days reduces moisture, minimizes humidity fluctuations, and prevents excessive odor buildup.

Growing Your Colony

Under ideal conditions, dermestid beetle colonies can expand rapidly. A single adult female lays around five eggs per day, with larvae reaching adulthood in 5–7 weeks. Each larva sheds its exoskeleton 5–11 times before pupating.

To accelerate growth:

  • Maintain a temperature around 77°F (25°C).
  • Ensure a constant food supply.
  • Provide pupation-friendly materials, like styrofoam.

Colonies with inconsistent food sources may experience cannibalism, where beetles consume eggs or pupae. Keeping them well-fed with ample hiding spots helps prevent this issue.

For optimal colony health and odor control, I recommend drying specimens before feeding. Placing them in front of a fan for a couple of days reduces moisture, minimizes humidity fluctuations, and prevents excessive odor buildup.

Cleaning the Colony

Managing waste is one of the more challenging aspects of dermestid beetle care. My preferred method for colony cleaning involves starving the beetles for a few days, then using food bait on an egg carton to gather them. Here’s my process:

  1. Place fresh food on an egg carton in the enclosure.
  2. Wait about an hour for beetles and larvae to climb onto it.
  3. Collect the egg carton and shake the beetles into a separate container.
  4. Repeat every few hours over a couple of days until most beetles have been transferred.

Once the majority of beetles are removed:

  • Dispose of the substrate while wearing a dust mask or respirator (fine beetle sheds can be harmful if inhaled).
  • Scoop out or sift the used bedding into a garbage bag.
  • Compost larger paper pellet and aspen bedding pieces if desired. However, avoid composting fine frass mixed with styrofoam particles.

For those looking to recycle frass and waste, a water separation method can be used:

  1. Fill a container with water.
  2. Dump in the sifted contents—styrofoam will float while frass and waste will sink.
  3. Remove floating debris and dispose of it.
  4. Pour the remaining water onto a garden or compost pile (note: this process can be smelly).

Once the enclosure is cleaned, wipe it down, recreate the substrate layers, add fresh food, and reintroduce the beetles. If managing multiple colonies, newly transferred beetles can be placed in a separate enclosure or added to an existing one.

By following these guidelines, you can maintain a healthy, efficient dermestid beetle colony for skull cleaning or other uses.