A flash of electric blue darting under a woodpile stops most people in their tracks, usually followed by a question about whether it was venomous. It almost certainly wasn't a snake at all: that blue tail belongs to a juvenile five-lined skink, one of the most widespread lizards in the eastern half of the country, and the tail color has nothing to do with danger and everything to do with staying alive long enough to grow up.
The Detachable Tail Strategy
Young five-lined skinks and several related skink species have bright blue tails specifically because predators strike at movement and color, and a skink's tail is built to detach cleanly along a pre-formed fracture point when grabbed, continuing to writhe on its own for a short while after separation. That wriggling decoy buys the skink itself, now tailless but alive, enough time to escape into cover. The tail regrows over subsequent months, usually shorter and less vividly colored than the original, and a skink can typically only pull off this trick a limited number of times before the fracture points are used up.
As skinks mature, the vivid blue fades into an olive-brown or bronze body color, often confusing people who assume the blue-tailed juvenile and the drabber adult are different species entirely.
Fence Lizards and the Push-Up Display
Eastern and western fence lizards are the ones most often seen doing rapid push-ups on a fence post, rock, or sunny patch of siding. That behavior is a territorial and courtship display rather than exercise: males have blue patches on the throat and belly that flash into view during the display, used to signal to rival males and to females. Fence lizards are strict baskers, needing direct sun to regulate body temperature, which is why they're reliably found on the same handful of warm, exposed perches in a yard rather than scattered randomly through shade.
Western fence lizard blood contains a protein that kills the bacterium responsible for Lyme disease inside the ticks that feed on the lizard. In regions where fence lizards are common, this has been documented to measurably reduce the local rate of infected ticks, an unusual case of one reptile's blood chemistry affecting disease risk for an entirely different set of animals, including people.
What Backyard Lizards Actually Eat
Nearly all common backyard lizards and skinks are insectivores, eating crickets, beetles, spiders, small moths, and similar invertebrates, with larger species occasionally taking small vertebrates opportunistically. None of the common backyard species in the continental U.S. are venomous or capable of delivering any harmful bite to a person; the worst outcome from handling one is usually a pinch and, if it's a skink, an involuntary tail drop that the animal will regrow.
- Leave rock piles and loose stone walls in place — both skinks and fence lizards use gaps between stones as retreats and hibernation sites
- Keep a few open, sun-exposed perches available — fence lizards specifically need direct basking spots to thermoregulate
- Avoid broad-spectrum insecticide use — it removes the prey base lizards depend on
- Never handle by the tail — even a gentle tail grab can trigger an unnecessary autotomy in skinks
Telling Them Apart From Salamanders
Lizards and salamanders are sometimes confused at a glance since both are small and low to the ground, but the distinction is straightforward once you know what to check: lizards have dry, scaly skin and visible claws on their toes, while salamanders have smooth, moist skin and no claws at all. Lizards are also reptiles that bask openly in the sun, while most salamanders avoid direct sun and stay under cover or near water to keep their permeable skin from drying out. A five-lined skink sunning on a rock and a salamander under a nearby log are occupying the same general habitat but living completely different daily routines, one built around heat and the other around moisture.
Seasonal Patterns Worth Knowing
Backyard lizards are ectothermic, meaning their activity level tracks ambient temperature directly rather than following an internal thermostat the way a bird or mammal's does. Cool mornings typically show little lizard activity until direct sun warms a favored basking rock or fence rail enough to bring body temperature up to an efficient operating range, after which activity picks up sharply through midday before tapering again as afternoon heat peaks in summer. In regions with real winter cold, both skinks and fence lizards brumate, a reptile equivalent of hibernation, sheltering below the frost line in rock crevices, rotting logs, or burrows and emerging again only once soil and air temperatures climb reliably in spring. A yard that seems to have lizards vanish completely from late fall through early spring hasn't lost its population; the animals are simply underground and inactive, waiting out conditions they're not built to be active in.