Owls are carnivores, and across nearly every species, small mammals make up the bulk of the diet — voles, mice, rats, and shrews taken on the wing at night. From there, the menu changes a lot by species: a saw-whet owl eats mice barely bigger than itself, while a great horned owl will take a full-grown rabbit or a skunk.
The short answer: small mammals dominate
Most North American owls are rodent specialists first. Voles are the single most common prey item across barn owls, great horned owls, and many other species, with mice, rats, and shrews filling out the rest of the mammal share. Smaller owls round out that diet with insects, and a handful of species regularly take amphibians, birds, or larger mammals when the opportunity is there. Diet tracks two things: the owl's size and the habitat it hunts in.
How owls hunt: silent flight and precision
An owl's hunting style is built around one advantage — it can approach prey without being heard. Specialized, comb-like serrations on the leading edge of the wing feathers, combined with a soft, velvety surface, break up the turbulence that normally creates flight noise. Add in exceptional low-light vision and a facial disc that funnels sound toward asymmetrically placed ears, and an owl can pinpoint a vole moving under grass or snow from a perch several yards (meters) away. Most owls hunt using a perch-and-drop approach or a slow, quartering flight low over open ground, then strike feet-first with enough force to kill on impact.
That precision is also why an owl box makes such an effective, low-effort form of natural pest control for a property with a rodent problem — the birds are already built for exactly that job.
What different owl species eat
Ask "what do owls eat" and the honest answer is "it depends which owl." Here's how diet breaks down by species commonly found across the US.
Barn owl
If you're wondering what do barn owls eat, the answer is about as close to "pure rodent" as it gets in the bird world. Barn owls are among the most specialized small-mammal hunters anywhere, with voles and mice typically accounting for the large majority of what they bring back to the nest. They hunt open fields, pastures, and marsh edges by sound as much as sight, which is part of why they take up residence readily in nesting boxes placed near open, huntable ground.
Great horned owl
The great horned owl is the generalist of the group and by far the most powerful hunter on this list. Its diet regularly includes rabbits, hares, and squirrels, and it's one of the few owls capable of taking prey as large as skunks, geese, or other raptors — including smaller owls. If you have a healthy squirrel population on your property, don't assume they're safe from every owl overhead; a great horned owl is well-equipped to make a meal of one. (Curious what's actually living in your yard? Here's a rundown of the different types of squirrels you might be seeing.)
Eastern screech owl
Much smaller and far more flexible in its diet, the eastern screech owl leans heavily on large insects — moths, beetles, and crickets — along with small mammals, small songbirds, and amphibians like frogs. Because it's compact enough to hunt in wooded backyards and suburban tree cover, it's one of the species most likely to actually take up residence in a well-placed habitat box. There's more on this species' habits in 5 things you didn't know about eastern screech owls.
Snowy owl
What do snowy owls eat depends heavily on where you're watching one. On their arctic breeding grounds, snowy owls rely on lemmings to the point that lemming population cycles directly drive how many owls breed in a given year. Outside the breeding season, when snowy owls move south into open fields and coastlines across the northern US, their diet broadens to voles, mice, rabbits, and waterfowl or other birds they can overpower in open terrain.
Northern saw-whet owl
One of the smallest owls in North America, the saw-whet owl hunts prey scaled to its size — deer mice and other small rodents make up most of its diet, with insects taken occasionally. Its hunting range and prey size stay modest compared to the larger species on this list, which is part of why it can go undetected in wooded backyards for years.
Owl pellets: a window into an owl's diet
Owls swallow smaller prey whole and larger prey in big pieces. The parts they can't digest — fur, feathers, and bone — get compacted in the gizzard and regurgitated as a pellet, usually a few hours after feeding. Unlike scat, a pellet is dry, tidy, and often intact enough to pull apart by hand.
Finding pellets below a roost or box is one of the clearest signs of who's living there and what they've been eating. Pulling one apart typically reveals:
- Small mammal skulls and jawbones, often intact enough to identify the species
- Fur, matted together with finer bone fragments
- Bird feathers or beak fragments, for species that take avian prey
- Insect exoskeleton fragments, mainly in pellets from smaller owls like screech owls
It's a genuinely useful way to confirm activity — and to figure out which species you're hosting — without ever needing to see the bird itself.
How much does an owl eat, and what that means for your property
Relative to body size, owls eat often. A single owl generally needs the equivalent of one to several rodent-sized meals a night to meet its energy needs, and that requirement climbs sharply once a pair is feeding a nest of growing owlets — parents hunt around the clock during that stretch to keep up with demand. Over a full season, a resident owl or nesting pair works through a meaningful volume of rodents, which is exactly why landowners with vole, mouse, or rat pressure treat owls as a working part of pest management rather than just a wildlife bonus.
None of this requires expertise to put to use. Choosing the right box for your local species and placing it correctly is most of the work — this comprehensive guide to attracting owls walks through both. If you're ready to give a resident hunter a place to nest, our owl box is built to species-specific dimensions that give barn owls, screech owls, and other cavity nesters a real shot at moving in.
