What if your pet was better at identifying medical problems than you were? What if they could sense a problem even before you had symptoms? Turns out, some animals can! From pigeons who sense cancerous cells, to dogs who can tell someone with diabetes when their blood sugar is dropping, animals can play a role in keeping us healthy and safe.

Just how animals are able to detect medical problems remains largely a mystery. But some say their power is based on an ability to sense changes in our behaviors and slight differences in how we smell. Some can even be trained to look for visual cues of illness. So, which animals are best suited for medical practice?

1. Pigeons

Detect: Breast cancer.

In a recent study from the University of Iowa, it was discovered that pigeons can be trained to detect cancerous cells. That doesn’t mean you should expect birds to fly around your head if you ever develop a tumor (that would be a bit too reminiscent of Alfred Hitchcock, anyway) — these birds were put to work in the lab.

Researchers put the pigeons in special chambers and trained them to differentiate between malignant and benign cancer cell slides, something that takes humans “considerable training to attain mastery.”

On day one of testing, pigeons were accurate about 50 percent of the time. By day 15, they had improved to 85 percent accuracy. The birds were particularly good at identifying breast cancer cells.

2. Mice

Detect: Bird flu.

China experienced an outbreak of bird flu — specifically, the H5N1 strain of avian flu, in 2006, which sent the world into panic about this little-known disease. Since then, U.S. researchers have found that mice can be trained to identify birds infected with the illness, possibly before they have the chance to spread it to humans.

The study, published in PLOS One, had mice identify the feces of infected ducks. The mice were rewarded when they correctly identified feces from ducks with avian flu. In the end, the mice were accurate 90 percent of the time.

11 Ways a Dog Can Save Your Life

3. Rats

Detect: Tuberculosis.

Tuberculosis was responsible for 1.1 million deaths in 2014, according to the World Health Organization. So it might come as good news that rats — specifically, giant African pouched rats — could successfully be used to identify a tuberculosis infection. Researchers have been working with these enormous rodents — who, like dogs, are also used to uncover landmines — to detect the disease, and with great success.

After a training period, the rats are considered “operational” and able to detect the disease 80 percent of the time. The researchers, who published their study in Behavioral Analysis, say this is particularly important because traditional TB testing can result in both false negatives and false positives. Research into using the rats on a more widespread basis is ongoing.

4. Fruit Flies

Detect: Cancer.

Would you believe that the humble (and also incredibly annoying) fruit fly is the most well-studied insect in the world of science? And because of that, we now know that these tiny, pesky pests may be able to detect cancer cells using their sense of smell.

According to research from Italy, the fruit flies react to the scents of certain cancer cells with changes in their antenna. Further, the study found that fruit flies can differentiate between different types of cancers, and even between different types of breast cancers.

5. Dogs

Detect: Lots of things!

Not a surprising entry into the world of animals with disease-detecting powers, man’s best friend is particularly adept at not only detecting problems, but helping to remedy them. Research has found dogs able to detect breast cancer in 88 percent of cases, and lung cancer with 99 percent accuracy. They’re also able to detect both high and low blood sugar levels in people who have diabetes. It’s believed that they’re able to make these detections because they can notice slight changes in the volatile organic compounds produced by humans.

And more than just detection, dogs can be trained to assist people who struggle with chronic conditions like diabetes or seizure disorders. Medical assistant dogs in particular are trained to retrieve medication and even call for help.

The Many Reasons Why We Need Service Dogs

Disease detection is a cornerstone of modern medicine, but is largely done with expensive testing and lab analysis. The next time you’re at the doctor’s seeking a diagnosis, imagine how much more… interesting the experience might be if members of the animal kingdom replaced traditional medical tests.