No animal can truly “dig through” cured, solid concrete. However, various animals can certainly damage concrete structures by exploiting existing weaknesses or by burrowing around and underneath them. Understanding these distinctions helps clarify how wildlife interacts with human-made environments.
The Reality of Animals and Concrete
Animals do not possess the biological capacity to excavate through solid, cured concrete. This material is too dense and rigid for animal claws or teeth to penetrate. Instead, animals typically cause damage by targeting concrete that is already compromised, such as areas with cracks, crumbling sections, or uncured portions. Rodents, like rats, have continuously growing incisors that require constant gnawing to maintain their length. They can gnaw through deteriorating or porous concrete, especially if desperate or seeking entry.
Beyond direct gnawing, a more common form of damage involves burrowing around or underneath concrete structures. Animals like rats, moles, groundhogs, and muskrats are natural diggers that seek shelter, food, or protection from predators. When these animals burrow beneath concrete slabs, foundations, or walkways, they displace soil, creating voids. These empty spaces compromise the stability of the concrete, which relies on a solid earth foundation for support. This undermining can lead to settling, cracking, or even the collapse of the concrete.
Groundhogs, for instance, can dig extensive burrow systems that are 2 to 6 feet deep and extend up to 50 feet long, with multiple entrances. Moles are also prolific diggers, capable of creating tunnels at a rate of up to 15 feet per hour. Muskrats, often found near water, can undermine concrete retaining walls or foundations adjacent to aquatic environments through their burrowing. The damage caused by these burrowing animals can be substantial.
Remarkable Animal Diggers
Many animal species exhibit extraordinary digging abilities in natural terrains. These animals are often referred to as fossorial, meaning they are adapted to digging and live primarily underground. Their burrows serve various purposes, including shelter from predators and harsh weather, places to store food, and safe havens for raising young.
Moles, for example, are highly specialized subterranean mammals. They construct complex networks of tunnels primarily to hunt for worms and grubs. They can dig at impressive speeds, with some species tunneling 12 to 18 feet per hour. Groundhogs, also known as woodchucks, create elaborate burrows with distinct chambers for nesting, waste, and food storage. Their burrows can be quite extensive, reaching depths of 6 feet and lengths of 15 to 25 feet, or even 50 to 100 feet when including all connected tunnels.
Badgers are another group of formidable excavators. American badgers are renowned for their speed and power, capable of digging faster than any other mammal. They can tunnel through hard-packed soil with remarkable efficiency. European badgers also construct vast underground complexes called “setts,” featuring numerous entrances and hundreds of feet of tunnels. Aardvarks, native to Africa, are exceptionally strong diggers, capable of rapidly excavating burrows for shelter or to access their primary food source: ants and termites.
Adaptations for Extreme Digging
Fossorial animals often exhibit a fusiform, or spindle-shaped, body that tapers at both ends, allowing for efficient movement through dense soil. Their limbs are typically short and stout, prioritizing strength over speed, which is beneficial for generating the force needed to move earth.
A defining feature for many diggers is their powerful forelimbs and specialized claws. Moles, for instance, have broad, spade-like forefeet with long, strong claws that are permanently turned outward, enabling them to scoop and push soil effectively. Badgers possess robust shoulders and thick necks, along with long, curved front claws that act like shovels, while their shorter back claws help clear excavated material. Their powerful muscles in the shoulders and forelimbs provide the necessary force to dig through tough ground. Aardvarks have extremely strong claws, described as being stronger than a pickaxe, which are essential for breaking into hard termite mounds and excavating burrows.
Some burrowing animals also have unique adaptations to protect their senses. Moles have small eyes with limited vision, suitable for their dark underground environment, and their fur lacks a defined nap, allowing them to move backward or forward within tight tunnels. Badgers have a transparent nictitating membrane that covers their eyes, protecting them from dirt and dust while digging. Rodents, like rats, possess continuously growing incisor teeth that are exceptionally strong, enabling them to gnaw through various materials, though they primarily target softer or compromised substances.