Ground Squirrel (Mexican & Spotted)

Both species are placental mammals with live birth, not insects, so there is no larval or pupal stage. Where the two species' timing or numbers differ, both figures are given rather than averaged.

Size is the fastest first sort

The Mexican ground squirrel runs 11 to 15 inches in total length and 7.7 to 14 ounces. The spotted ground squirrel is one of the smallest ground squirrels in North America, about 7.3 to 10 inches long and only 3.5 to 4.4 ounces, noticeably smaller even at a glance.

Spot pattern is the confirming detail

The Mexican ground squirrel carries nine straight, organized rows of squarish white spots running the length of its brown to olive-gray back, plus a white ring around each eye. The spotted ground squirrel's white spots are scattered and irregular, never arranged in rows, on a smoke-gray, light drab, or fawn-colored back, and can be faint on the shoulders.

Ears and tail

The Mexican ground squirrel has small, rounded ears and a flattened, moderately bushy, grayish-white and black tail less than half its total body length. The spotted ground squirrel has inconspicuous ears and a shorter tail, about a third of its total length, pinkish buff or cinnamon underneath and black at the very tip.

Burrow entrances are the same story for both

Neither species piles dirt at the burrow mouth the way many other burrowing rodents do. A 2 to 3 inch, unmounded hole with no visible spoil pile, often with a second entrance nearby, is a strong sign one of these two species (or a related ground squirrel) is present, even before the animal itself is seen.

The thirteen-lined ground squirrel

Commonly confused with the thirteen-lined ground squirrel (Ictidomys tridecemlineatus), a separate species with its own Midwest, Mountain West, and South Central range. That species combines solid stripes with rows of spots down the back; neither the Mexican nor the spotted ground squirrel has stripes at all.

The rock squirrel

Commonly confused with the rock squirrel (Otospermophilus variegatus), another separate species. The rock squirrel is much larger, 18 to 21 inches long, and sticks to rocky cliffs, boulders, and canyon walls rather than the flat grassy or brushy ground the Mexican and spotted ground squirrels prefer.

Unmounded burrow entrances

They run 2 to 3 inches across.

Daytime sightings

Daytime sightings of a small, upright rodent near the burrow, in gardens, along fence lines, on golf courses, in cemeteries and parks, or on road shoulders. Both species are active by day, and the spotted ground squirrel in particular is most visible in early morning and late afternoon, retreating underground during peak midday heat.

Garden and landscape damage

Garden and landscape feeding damage, chewed flowers and vegetables, and disturbed newly planted seed beds.

Rural and agricultural signs

These are the ones that show on working land.

A shrill alarm whistle

It comes from the Mexican ground squirrel. No distinctive odor is associated with either species.

Let the grass grow

Both species prefer short grass. Allowing lawn or pasture grass to grow into denser, taller stands changes the habitat enough to discourage new burrows, and tilling or cultivating infested ground destroys existing burrow systems outright.

Time plantings around activity

Time plantings around peak activity. Putting in grain or garden seed as early as weather allows gives seedlings a head start past the vulnerable sprouting stage before the squirrels are fully active for the season.

Fence the high-value areas

Fence small, high-value areas. Sheet metal or half-inch hardware cloth, at least 18 inches tall with about 6 inches buried below grade, fully surrounding the protected bed, works for gardens and flower beds. This is a small-area method, not a whole-yard solution.

Trap a small population

Trap where the population is small. Cage traps or ordinary rat traps, baited with grain or oats and set near the burrow entrance, are a practical homeowner-scale option, especially in urban settings where a toxicant is not appropriate. An unbaited expanded-trigger trap placed directly in the animal's travel path also works.

Flooding a burrow

A few gallons of water can encourage the animal to relocate, a lower-cost non-lethal option where that is practical.

On trapping and relocation

Trapping ground squirrels is legal at any time in Texas, but if you plan to live-trap and relocate the animals rather than remove them, notify your local Texas Parks and Wildlife Department office first.

Call for chemical control

Call a licensed pest control operator for chemical control. Rodenticides effective against ground squirrels are restricted-use in many formulations and, per Texas A&M AgriLife guidance, may only be applied by a licensed operator or a properly licensed private applicator.

Call for burrow fumigation

Call a professional for burrow fumigation, and never attempt it near occupied structures. Fumigation requires a documented fumigation management plan and enough soil moisture to hold the gas in the burrow. It should never be used under or near buildings, because fumes can seep indoors and create a hazard to occupants.

When to escalate to a pro

Escalate to a licensed pest or wildlife control professional if burrowing is undermining a foundation, a dam, or an irrigation levee, or if the population is outpacing habitat modification, timing, and trapping efforts on its own.