Decay: A Symphony of Scents

Step into any natural history museum, and you're surrounded by remnants of life - animals seemingly frozen in time, insects meticulously pinned, and of course lively visitors learning together. All seems to be properly organized, even clean. Further behind the curtain, into the often-untidy storage cabinets and collection of odd animal parts, the unmistakable olfactory experience of decay wafts out to remind us of the messiness of life and death.

To us, the sensation of decay in the air is troubling, often repulsive. But it’s also an important reminder of the fascinating process that ties life and death together.

Though some salvaged animals are visually "fresh," they often carry
a particular scent of decay that builds as they thaw for taxidermy.

When an animal passes away, their body begins to break down almost immediately. This decomposition occurs in stages and each one contributes to that pungent aroma that so many of us associate with death. With frequent exposure to animal bodies in various stages of decomposition, from colorful little songbirds who struck a window to a beautiful fox kit who’s body was badly broken from a car collision, I’ve smelled a lot of decay. 

In the early moments, as the body starts to decompose, something interesting happens – the animal’s cells begin to break apart. It’s as if the animal’s body is slowly digesting itself. As this happens, bacteria, enzymes, and microorganisms get to work, breaking down tissues and releasing compounds as fun, smelly gases like methane, hydrogen sulfide, and ammonia.

The larvae of Dermestid beetles are especially interested in feasting on the Museum's
taxidermy collection, and we go to great lengths to prevent them from entering our domain. 

As the body continues to decay, larger scavengers like beetles, maggots, and even my beloved fungi begin to feed, each doing their part to break down flesh and tissues. And with this, the odor intensifies. Compounds like putrescine and cadaverine begin to take over. These two compounds are the hallmark stench of rot. For us humans, it’s an unmistakable scent that signals decomposition, but for certain creatures, it’s an invitation to dine.

Here in my workplace, decay isn't just something that happens in nature. It’s part of the process of preserving specimens for our collection. Whether it’s the whiff of our live raptors’ rat breakfast, or the early stages of a taxidermy project, the smell of decay often occupies both public and private spaces.

For taxidermists and naturalists alike, dealing with the smell is just part of the job.
The Collections Look-in Lab regularly emits an odor of both decay and discovery!

While the smell of decay might make us shy away from some activities, for other animals, it’s an exciting call for dinner. Turkey vultures, blowflies, and certain species of beetles are specially evolved to be drawn to the scent of decomposing flesh. To them, it’s a signal—a scent trail leading to a delicious meal. For blowflies, it’s even more critical as they rely on decay to find places to lay their eggs, ensuring that their larvae have fresh food once they hatch.

And the turkey vultures? Their preference for smell was one of the first tidbits of information my co-intern delighted in sharing with me the first day I worked at the Museum. Amazingly, they follow the smell of death for miles, swooping in to clean up the environment by feasting on carrion, stopping disease from spreading. To them, decay is life.

While the smell of death may be overwhelmingly unpleasant to us humans, it plays a crucial role in the natural world. Decay’s symphony of scents serves as a reminder that life and death are intricately intertwined.