Imagine a bear that can smell its way through concrete and literally inhale its dinner like a high-powered vacuum. It’s the sloth bear: the world’s most specialised insectivore. At first glance, the sloth bear appears to be like any other bear — shaggy, strong, and unmistakably wild. However, if you look closer, you’ll notice something unusual. Its long lips protrude forward, its snout is flexible, and its front teeth seem incomplete.
Although capable of being active at any time of day, sloth bears are most often seen foraging at night, particularly in areas with high human activity. [Photo © Wildlife SOS/ Sanjeev Marskole]
This is no accident of nature! Sloth bears are myrmecophagous, meaning they enjoyably eat ants and termites. Unlike many other bear species that depend heavily on fruits, vegetation, fish, or larger prey, sloth bears have evolved with unique adaptations for feeding on these insects. Their anatomy is fine-tuned for the sole purpose of extracting tiny prey from some below the sand or from crevices of the toughest of natural structures in the forest. Their wild favourites also include fruits, plants and honey (remember Baloo from The Jungle Book?), but observations have also been made of sloth bears scavenging carrion, making them fall under the omnivorous category as well.
The No-Teeth Advantage
In the wild, survival usually depends on having the biggest, sharpest teeth. To make sure they live up to their exclusivity, it seems sloth bears decided to go the opposite way. Their most striking aspect of evolution is the absolute absence of upper central incisors. While it might appear they’re giving us a gap-toothed smile, the missing teeth create a natural ‘suction nozzle’ that allows insects to be pulled up through it with remarkable efficiency.
Because of the absence of the incisors, sloth bears have a unique dental formula, a mechanism by which dental arrangement for all mammals is defined. For humans, the standard formula is 2/2, 1/1, 2/2, 3/3, indicating that there are 2 incisors, 1 canine, 2 premolars and 3 molars in both the upper and lower jaw, which gives us the total of 32. For sloth bears, the formula is slightly different:
2 × (2/3, 1/1, 4/4, 2/3) = 40 teeth
Which means:
Upper jaw: 2 incisors, 1 canine, 4 premolars, 2 molars
Lower jaw: 3 incisors, 1 canine, 4 premolars, 3 molars
What looks like missing pieces in their dental structure is, in fact, one of their greatest strengths. After powerful exhalations that blow dust or debris away, sloth bears use their flexible lips to form a tight seal on the mouth through which they forcibly inhale. This creates a vacuum-like mechanism. Within moments, thousands of termites can be sucked up.
A closer look at the sloth bear’s flexible snout and lips that are perfectly adapted to vacuum insects from deep within termite mounds. [Photo © Wildlife SOS]
Unlike most mammals, they can even close their nostrils voluntarily while feeding! This is a smart ability that prevents dust and insects from entering their nasal passages. If they could enter, sloth bears would be victims of sneezes and bites! It’s a crucial detail that makes their feeding technique commendable.
The Acoustic Hunter
Finding termites is not as simple as it sounds. Termite mounds can be rock-hard, which is why they are often labelled as natural concrete structures. Sloth bears rely heavily on their acute sense of smell to detect insect colonies beneath the surface. Their eyesight and hearing are relatively poor, but their refined olfactory ability allows them to locate prey that is hidden underground.
With sickle-shaped claws and powerful swipes, sloth bears can break open even the hardest termite mounds. [Photo © Wildlife SOS]
Before the vacuum can start, the bear has to unlock the vault. Imagine Marvel Comic’s mutant character Wolverine extending his claws, ready to attack. Claws of sloth bears can extend up to 4 inches, but unlike Wolverine’s, they aren’t retractable, and remain ready to dig into mighty mounds. What helps them further is the sickle-shape of their claws, which comes in handy to not only scoop termite mounds and anthills, but also to climb trees or catch fish.
This combination of smell and strength transforms them into efficient foragers as well, capable of accessing food sources that remain untouched by most other species.
The Sound of Success
If you’ve ever stood near a sloth bear enclosure during their meal time at our Bannerughatta Bear Rescue Centre or Agra Bear Rescue Facility, you’re sure to hear them before you see them. A sloth bear’s eating process produces a loud slurping and snorting sound, so distinct that it can be heard from over 100 metres away! What causes it? The sound of air that is drawn in as the bear vacuums insects into its mouth.
The slurping noise of a feeding sloth bear is one of the most distinctive sounds in the forest that are often carried across surprisingly long distances. [Photo © Wildlife SOS]
This audible feeding behaviour is unlike anything observed in other bear species. Since it is repeated a number of times during a single meal, it makes for a vocal performance by bears when they’re heard collectively at our centres. Amidst nature’s version of silence in the forest, this sound becomes a sign conveying a sloth bear at work. Fortunately for the sloth bear, its thick, shaggy fur provides a protective barrier, helping it withstand the bites from swarms of angry insects that emerge when their mound is breached.
Nature’s Unsung Engineer
Beyond their fascinating feeding habits, sloth bears play a crucial ecological role. By breaking open the termite mounds and anthills, they help regulate the insect populations that could otherwise grow unchecked. As they dig and forage, sloth bears aerate the soil, improving its structure and circulating nutrients. This natural behaviour supports plant growth and contributes to the overall forest health. In a way, we can imagine that as they hunt to eat, sloth bears are playing the role of wild gardeners.
At the Bannerghatta Bear Rescue Centre (BBRC), dedicated termite and mealworm cultures help provide rescued sloth bears with species-appropriate nutrition while encouraging their natural foraging instincts.
Sloth bears are not just insect hunters, they are ecosystem engineers, quietly shaping the landscapes they inhabit. [Photo © Wildlife SOS/ Abhiman]
A Specialist Worth Protecting
Being a myrmecophagous species is risky in a changing world. Despite their amazing adaptations and qualities, sloth bears are facing several growing challenges in the wild. Habitat loss, human-wildlife conflict, and historical exploitation have all impacted their populations. With fragmented forests, the sprawling termite colonies these bears rely on are disappearing rapidly too. Wildlife SOS has closely studied this bear species to understand the reasons behind bears wandering into villages and garbage dumps to get their meals, and it is not because they simply wish to. Deprivation of habitat and its resources are pushing them closer to human spaces where food can be easily accessible so they can survive.
Safe, comfortable and at peace – this is the future we at Wildlife SOS strive to create for every sloth bear of India. [Photo © Wildlife SOS/ Vineet Singh]
At Wildlife SOS, sloth bears rescued from conflict situations are given a second chance. Opportunities to explore their natural behaviours, like foraging and digging, are encouraged through enrichments and care practices, allowing them to retain and express their wild instincts.
Awareness is key to understanding animals, with each playing a key role in the wild. Sloth bears happen to be one of the most understudied bears among the eight species that exist across the world. The more we explore the species, the more we get to know of their distinctive behaviour and anatomy. Knowledge of these is the first step toward respecting their place in the wild.
From climbing structures to insect-based enrichments, every activity is designed to encourage the instinctive behaviours that make sloth bears unique. [Photo © Wildlife SOS/ Abhiman]
We can bet that the next time you hear someone slurping an ice cream, you’ll be reminded of the suction sound a sloth bear makes while feeding! Their feeding finesse took all of 4 million years to perfectly evolve. You can join Wildlife SOS in safeguarding these exceptional species through conservation efforts. Donate now to protect a species that helps keep ecosystems in balance.
Feature Image: Wildlife SOS
