3 things you should know about antlers, what you should be flushing down the toilet, and electron rain
Meet Michelle Campbell Mekarski, Cassandra Marion, and Renée-Claude Goulet.
They are Ingenium’s science advisors, providing expert scientific advice on key subjects relating to the Canada Science and Technology Museum, the Canada Aviation and Space Museum, and the Canada Agriculture and Food Museum.
In this colourful monthly blog series, Ingenium’s science advisors offer up three quirky nuggets related to their areas of expertise. For the December edition, they explore what antlers can tell us about Santa's reindeer, what you shouldn't be flushing down your toilets this holiday season, and how lightning on earth can cause electron rain in space.
The truth behind Santa’s reindeer: it’s all about the antlers!
With the holiday season in full swing, antlers and reindeer start popping up everywhere as quintessential symbols of Christmas and winter festivities. But here’s a fun twist—Santa’s reindeer are likely all female, according to science! Why? It’s all about the antlers!

A Boreal woodland caribou still sporting its antlers in winter (Rangifer tarandus caribou)
First off, what exactly is a reindeer? While they might seem mythical, we’re more familiar with them than you think. In Canada, they appear on our 25-cent coin, though here, we call them caribou. Fun fact: only farmed caribou are referred to as reindeer in Canada. These animals belong to the species Rangifer tarandus, known as reindeer on the European continent. Small but mighty members of the deer family, they hold immense cultural significance for Indigenous peoples and their ways of life. Unfortunately, caribou populations in Canada are endangered due to human activity, namely habitat loss from resource extraction like logging, and climate change. Until the 1960s, all caribou and reindeer were considered one species, but, with genetic analysis tools available today, a scientist has reclassified Canadian caribou into distinct species and subspecies to better tailor conservation efforts, since different groups found here have different habitats, survival strategies, and sizes.
Now, let’s talk antlers. Reindeer, like other members of the deer family (moose, elk, red deer, etc.), grow antlers. Unlike horns—which are permanent, covered in keratin (the same protein in your nails and hair), and found on both males and females—antlers are made of bone, shed every year, and regrown. Among deer, only male animals grow antlers... except for caribou, where both males and females sport them. Intrigued? Let’s dig deeper.
The process of shedding antlers is triggered by seasonal light changes. As daylight decreases, the pineal gland in the brain lowers testosterone levels, forming a weakness in the connective tissue at the antler's base, called the pedicle. This causes the antlers to fall off. Shortly after, they start regrowing, covered in a layer of fuzzy skin called velvet, which brings the blood and nutrients necessary to the growing bone. Once the bone is fully formed, the velvet sheds, and the antlers are ready to impress. Annual shedding allows deer to grow stronger, larger antlers and replace broken or worn-down ones.
And here’s a cool ecological tidbit: shed antlers don’t go to waste. They decompose and feed the ecosystem, providing nutrients to the soil and even a snack for small animals.
So, why do deer grow antlers in the first place? Male deer use them to spar and establish dominance among each other and impress potential mates. And, since antlers demand a lot of energy and nutrients to grow, a magnificent set also signals a deer in good health and with access to plenty of food.
In caribou, they serve an additional purpose. Like other deer species, male caribou shed theirs in the late fall, after the mating season (called the rut). Females, on the other hand, keep theirs through the harsh winter, only shedding them in spring.
Why the difference? It probably has to do with their resource-scarce habitat. Female caribou are pregnant over the winter months, and rely on their antlers for survival and successful gestation of their calves. Living in northern regions with long, snowy winters, they use their antlers to dig through snow for food, defend small feeding patches, and protect themselves and their calves from predators, like wolves.
So, there you have it—Santa’s reindeer, still prancing around with antlers in December, are most likely female. The creators of the classic holiday tales maybe weren't aware of this slight precision in deer world, but hey, now we have a fun fact to share at our next holiday parties! Happy holidays!
By Renée-Claude Goulet
To flush or not to flush, that is the question
Ever wondered what happens after you flush? It may feel like waste disappears into a magical abyss, but what you flush has more of an impact than you might think. Flushing the wrong items can wreak havoc on your home, damage municipal wastewater systems, and harm the environment.
The Science of Clogs
Toilets and sewer systems are only designed for three things: human waste, toilet paper, and water. Toilet paper is specially engineered to break down quickly, keeping things flowing within the pipes. When items like diapers, wipes (even “flushable” ones!), or sanitary products are flushed, they don’t break down the way toilet paper does. Instead, they can get caught in bends and joints in your pipes. Once caught, they act as “nets,” trapping more debris and forming blockages.
It’s not just the city’s pipes at risk. The municipal sewer system is directly connected to your home’s plumbing. If clogs form in the larger network, wastewater can back up into homes or even flood entire neighborhoods. Imagine raw sewage seeping into your basement because one of your neighbours flushed a diaper. It’s a nightmare scenario, and one that’s entirely preventable.
Cooking oils, fats, and greases (FOGs) poured down drains and toilets add to the potential chaos. While they may flow easily when hot, they cool and solidify on the inner walls of pipes, sticking to items like wipes or plastics that have been flushed. Over time, these layers of FOGs and debris grow, forming a hard, impermeable plug—famously known as a “fatberg”—that can block entire sections of the municipal sewer system. When that happens, backups become inevitable, and the cost to repair the damage is enormous.

These are pictures taken March 17, 2020, from a sewage pumping station in London, Ontario, and show the contents of a clog, including wipes, gloves, bags, toys, and a tampon applicator.
Pharmaceuticals, Plastics, and PFAS: Invisible Pollutants
While visible clogs like fatbergs make headlines, invisible pollutants such as pharmaceuticals, plastics, and PFAS (per- and polyfluoroalkyl substances) present equally serious challenges. At treatment plants, these substances can slip through filtration systems and enter rivers and watersheds, where they disrupt aquatic ecosystems.
Hormones from pharmaceuticals can interfere with aquatic species’ reproductive systems, and antibiotics contribute to the growing problem of antibiotic resistance in the environment.
Plastics, including microplastics from flushed hygiene products, degrade slowly and break into tiny particles. These microplastics are ingested by fish and other aquatic animals, accumulate in the food chain, reach our own dinner plates, and get stuck in our bodies.
PFAS, or “forever chemicals,” are particularly troubling. Resistant to breaking down, they persist in water sources indefinitely, posing long-term health and environmental risks.
Toilets Aren’t Trash Cans
Appropriately disposing of your waste and only flushing the three Ps — pee, poop, and paper — protects your home, your wallet, and the environment. Start by keeping a wastebasket in your bathroom for non-flushable items. Dispose of grease and oil in a sealed container in the trash. Take unused medications to a pharmacy or hazardous waste facility instead of flushing them.
Every system is connected—from the pipes in your home to the city’s wastewater infrastructure and to the rivers and oceans beyond. When backups occur, they don’t just stay in the sewers; they can flood homes, damage property, and harm ecosystems. By making better choices, we can prevent blockages, protect vital infrastructure, and safeguard our waterways for future generations.
Next time you’re tempted to flush something questionable, think twice. Your plumbing—and the planet—will thank you!
By Michelle Campbell Mekarski
Go further:
Rethink the way you see human waste at the Oh Crap! exhibition, at the Canada Science and Technology Museum until January: https://ingeniumcanada.org/scitech/exhibitions/oh-crap-rethinking-human-waste
The Ontario Clean Water Agency's "I Don't Flush" campaign: https://www.ocwa.com/community-overview/i-dont-flush/
The Canadian Water and Wastewater Association (CWWA) encourages us to think about what we flush: https://cwwa.ca/covid-19-and-sewers-to-avoid-a-sewage-back-up-dont-treat-your-toilet-like-trash-can/
Learn about wastewater and where to dispose of certain types of waste in Ottawa: https://ottawa.ca/en/living-ottawa/drinking-water-stormwater-and-wastewater/wastewater-and-sewers/wastewater-education

Lightning strikes during a storm over Arizona, planet Earth.
Lightning triggers electron rain!
Yes, you read that correctly. Lightning on Earth can trigger space weather in the form of a shower of electrons falling on our atmosphere from space.
Our home planet is protected by a magnetosphere, a region dominated by our magnetic field that acts as a shield to block out harmful cosmic rays and solar wind from the Sun. Earth’s magnetic field traps charged particles from the solar wind, such as protons and electrons, which results in two donut-shaped regions called the Van Allen radiation Belts. The inner belt stretches from about 2,000 to 12,800 kilometers above Earth, while the outer belt lies between 19,000 and 40,000 kilometers above the surface. Our magnetic shield is not perfect however, and high-energy electrons from these radiation belts can still fall toward the planet. A recent study examined satellite measurements to show that these dangerous high-energy electrons can be knocked out of the inner radiation belt and rain down on the upper atmosphere. Strikingly, it is low-frequency radio waves, known as whistlers, generated by the powerful discharge of electricity that occurs as lightning, that trigger this phenomenon. These radio waves interact with electrons in the inner belt, setting them in motion between the poles, causing some to descend into Earth's atmosphere. Yet, many questions remain, such as how often these lightning-induced electron storms occur and whether they might be linked to increased solar activity.
High-energy electrons are a type of ionizing radiation which can be hazardous to both people and technology. They present a risk for satellites in low Earth orbit and for aircraft electrical systems; they can interfere with radio communications and GPS navigation; and they break down molecular bonds which can be extremely harmful to living cells. If a human, an astronaut for instance, is exposed to high levels of ionizing radiation, it can cause a variety of unpleasant symptoms to severe illness or death. For example, astronauts on the International Space Station, which orbits about 400 km over the Earth between the inner Van Allen belt and our atmosphere, can be subjected to increased radiation during both a solar storm or, now as it turns out, storms on Earth. Thankfully, there are already many interventions in place to reduce the risk to both people and technology. In most cases, improved space and Earth weather forecasts, good planning, and shielding make short term exposure to this radiation manageable.
By Cassandra Marion
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