Understanding the Garter Snake: Diet, Hunting Techniques, and Predators

One of the most common snakes throughout North and Central America, garter snakes (Thamnophis) are skilled hunters that feed on a variety of animals. These little snakes help the ecosystem by controlling rodent and insect populations, and gardeners love to have them around to keep pests away from their crops. So, what does the average garter snake eat, and how does it locate and take down its prey?

Foods Garter Snakes Eat

Like all snakes, the 30+ unique species of garter snakes are strict carnivores. This means they don’t eat plant matter and subsist solely on meat from other animals. 

Because they are one of the smaller varieties of snakes and lack powerful venom or the ability to constrict their prey, garter snakes prefer to hunt animals that are small and weak enough to be easily ambushed and swallowed whole. 

Garter snakes generally prefer live prey, but they may also eat freshly killed or recently dead animals, especially in captivity or if the prey is still warm. They will also occasionally eat eggs from smaller birds and reptiles because they are easy targets and have lots of protein.

Foods garter snakes eat regularly include earthworms, slugs, crickets, grasshoppers, salamanders, newts, lizards, small birds, minnows, rodents, snails, smaller snakes, and eggs.

How Garter Snakes Hunt Prey

Despite their small size, garter snakes are skilled hunters who use their lightning-fast reflexes to ambush their prey. They also have excellent sight and a keen sense of smell. Their sharp senses help them locate and stalk their prey without immediately alerting the prey animal to their presence.

A garter snake’s tongue rapidly darts out of its mouth and flicks at the ground and air, picking up scents and transmitting information about them to its vomeronasal organ (also known as Jacobson’s organ).

The vomeronasal organ then interprets the information, alerting the snake to what kind of prey is nearby and how far away it is (as well as helping to locate nearby predators). Once it has located its next meal, a garter snake will wait for the perfect moment to strike before swallowing the prey whole. It then uses the powerful muscles throughout its body to slowly move the animal down its digestive tract.

Although garter snakes were long considered to be non-venomous, more recent research has shown that their saliva contains a very weak neurotoxic venom. While weak, it is effective for hunting smaller animals. The venom is non-lethal to humans, especially since garter snakes lack the hollow fangs needed to effectively and reliably deliver it.

Animals That Prey on Garter Snakes

Because they are so small and lack defense mechanisms, garter snakes are commonly preyed upon by several larger animals, including other snakes.  Garter snakes have an array of mammalian, avian, amphibious, and reptilian predators, including:

• Foxes
• Bears
• Bullfrogs
• Raccoons
• Hawks
• Snapping turtles
• Crows
• Eagles
• Herons
• Owls
• Larger snakes like kingsnakes and coral snakes.

Despite their weakness and small size, garter snakes do possess one somewhat effective defense mechanism. They can emit a foul-smelling secretion from the glands surrounding their cloaca, which helps to deter certain predators.