The practice of using insects to prepare skeletal specimens has become the preferred method in natural history museums, forensic science, and taxidermy. Boiling or using harsh chemicals can weaken delicate bone structures, loosen teeth, and cause the bone to shrink or discolor. The natural feeding process of specialized beetles ensures that all soft tissue is removed while the underlying bone and cartilage remain perfectly intact. This gentle yet thorough cleaning preserves the specimen’s integrity.
The Specific Beetle Species Used
The primary organism responsible for this specialized cleaning is a member of the dermestid beetle family, specifically Dermestes maculatus, commonly known as the Hide Beetle. This species is favored by professionals due to its voracious appetite and its ability to consume nearly all forms of dried animal tissue. The larvae, which are the most active feeders in the colony, are particularly efficient at skeletonization, leaving behind a clean bone structure.
The Hide Beetle is chosen over other dermestid species because it possesses a rapid reproduction cycle and thrives in a controlled environment. A healthy colony can grow quickly, allowing for the rapid cleaning of large specimens, such as an adult deer skull, which may be finished in a matter of days or weeks, depending on the colony’s size. Unlike other dermestids, such as carpet beetles (Anthrenus spp.), which are difficult to cultivate, Dermestes maculatus is robust and easy to maintain. The beetles consume muscle, connective tissue, and dried membranes, ensuring the finished skull requires minimal post-processing work.
Preparing Skulls for Cleaning
Before a skull is introduced to the beetle colony, it must undergo several preparation steps to ensure the safety and efficiency of the cleaning process. The initial stage involves gross defleshing, where the preparer removes the skin and all major muscle masses using manual tools. This step is important because the beetles struggle to penetrate thick layers of tissue, and excessive amounts of flesh can rot before the insects can consume it, potentially contaminating the colony.
The eyes, tongue, and brain must be removed, as the beetles do not readily consume these parts, and their presence can cause foul odors and introduce excess moisture. The skull should then be allowed to dry or cure slightly. This drying ensures that the beetles are working on a more desirable food source and that no excessive moisture is introduced into the colony habitat.
A final step before placing the skull in the habitat is to freeze the specimen for at least 48 hours. Freezing eliminates any potential fly eggs, maggots, or external parasites that could have been present on the carcass and which could otherwise damage the beetle colony. Once prepared, the skull is ready to be placed directly into the colony for the beetles to begin their work.
Housing and Safety for Your Colony
Maintaining a thriving beetle colony requires environmental control, containment, and hygiene. The enclosure, often a secure plastic tote or chest freezer retrofitted for insulation, must be kept at a consistent temperature, ideally between 65°F and 85°F (18°C to 29°C), with the warmer end promoting faster feeding and reproduction. Humidity should be maintained at a moderate level, typically between 50% and 60%, as high moisture encourages the growth of mold and harmful mites.
The habitat requires a layer of bedding material, such as shredded paper, wood shavings, or Styrofoam, which the larvae use for pupation and the adults use for hiding. Proper ventilation is achieved by cutting holes into the container and covering them with a fine mesh screen, which provides airflow while preventing the beetles from escaping their enclosure. Because adult Dermestes maculatus can fly when temperatures rise above 80°F, fine mesh is essential for security.
When the beetles are not actively cleaning a skull, they must be fed raw, unsalted meat or animal material to maintain colony strength and encourage reproduction. Avoid introducing specimens treated with high-salt brines or antiparasitic drugs, as these substances can be toxic to the beetles. Regular cleaning to remove debris and frass is important for preventing mite infestations and allergic reactions from the fine, airborne larval hairs.