Why Do Chipmunks Chirp? What Each Sound Actually Means

That relentless, bird-like chipping from somewhere near the woodpile is an alarm call, and it is almost certainly about you, the cat, or a hawk. Chipmunks have different calls for different threats, and you can read them from a window.

The three sounds

The chip is the one that brings most people to this question, because it is astonishingly loud for an animal that weighs about three ounces, and because it can continue unbroken for twenty minutes or more.

Why it goes on so long

Because the predator has not left.

The call is not a single announcement. It is a sustained broadcast, kept up as long as the caller can still see the threat, which does two things at once: it warns every chipmunk in earshot, and it tells the predator it has been spotted. Many ambush hunters give up once they have lost surprise, so the call is also aimed at the cat.

Yes, it is about you

Chipmunks do not make fine distinctions among large ground predators, and a person weeding a bed ten feet from a burrow entrance is, as far as the animal is concerned, the same category of problem as a fox.

It costs the chipmunk nothing but time, and it will go back to feeding once you have been stationary and boring for a few minutes. Sitting still on a step is the fastest way to end the alarm and usually the best way to watch them.

What else is calling in your yard

Two frequent misidentifications:

“A chipmunk is chirping at night.” Chipmunks are strictly diurnal and are underground by dusk. Night calling is almost always tree frogs, crickets, katydids or a screech owl, whose trill fools people regularly.

“A bird is chipping for twenty minutes.” Often this is the chipmunk. A sustained, unvarying, metronomic chip from low down near cover is far more likely a chipmunk than any bird.

Red squirrels also chatter and scold loudly, at greater length and with more variety, usually from higher up.

What the calling tells you about the yard

A yard with a lot of chipmunk alarm calling usually has one or more of:

• A resident cat using it as hunting ground
• A hawk — a Cooper’s or sharp-shinned hawk working the feeders
• A bird feeder, which supports far more chipmunks than the yard would otherwise carry, and which draws the hawks in turn
• Good cover: stone walls, woodpiles, retaining walls, dense shrubs

If the burrowing is the real problem

The calling is seasonal and threat-driven; the tunnelling is what actually causes damage. If chipmunks are undermining a patio base, a retaining wall or a foundation:

• Cut the food supply. Spilled birdseed is the single biggest driver of high chipmunk density. Sweep it up, use no-mess seed, or pause feeding.
• Gravel, not soil, in a band against foundations and under decks — they dislike digging it.
• Quarter-inch hardware cloth over vents, and buried as an L-shaped apron along vulnerable walls.
• Remove cover immediately against structures: woodpiles, dense groundcover, stacked materials.

That last list, unlike trapping, actually holds — remove one chipmunk from a yard with spilled seed and good cover and another one arrives inside a fortnight.