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Farming is one of humanity's greatest innovations. By growing crops, we could create stable settlements with a consistent food supply. Surprisingly, humans aren't the only clever creatures to come up with this idea. In fact, in the animal kingdom, we are newcomers to this practice.
Here are 10 animals that might be considered farmers. While many of these interactions could be seen as symbiotic and mutually advantageous, ultimately, one side of the partnership ends up consuming the other.
10. Leaf Cutter Ants
Ants in the Antinni tribe, including species like Cyphomyrmex longiscapus and Cyphomyrmex muelleri, rely on the fungi they cultivate. In fact, there are over 78 species of fungus-farming ants.
Leaf cutter ants create a vibrant and fascinating scene as they march across the forest floor, carrying large leaf fragments above their heads. But these ants don’t eat the leaves they chop up and carry home. Instead, they use them to nourish their fungus gardens. Once the fungus has absorbed all the nutrients from the leaves, the ants discard the waste into trash piles. Additionally, these ants produce antimicrobial substances to protect their fungi.
The fungi crop serves as the colony's primary food source, providing nourishment for the ant larvae. The importance of this crop is so great that when a new queen begins a colony, she takes a piece of the fungus to start a new garden. The ants grow their crops in environments unsuitable for wild fungi, and as such, they cultivate a monoculture of fungus while using bacteria to ward off parasitic fungi that might otherwise invade their crops.
9. Herder Ants
Ants don’t just farm crops for food; some species also manage livestock. For example, species like Crematogaster scutellaris care for colonies of aphids, which they milk for honeydew. Honeydew is a sweet, sugar-rich secretion produced by aphids as they feed on plant sap. To collect this honeydew, ants gently stroke the aphids, causing them to release the sugary liquid.
Ants don’t simply exploit aphid colonies they find by chance. They actually manage their own herd of aphids, ensuring they stay on the lower parts of the plant to access the juiciest sap while protecting them from predators by keeping them sheltered beneath leaves. Research has shown that chemicals found in the ants' footprints have a calming effect on aphids, keeping them relaxed and preventing them from straying from the herd.
In a darker twist, ants are known to bite the wings off aphids to keep them from flying away. During the winter, some ant species bring aphid eggs into their nests to protect them from the cold, ensuring their herd survives through the harsh temperatures.
8. Termites
The history of termite farming is truly remarkable, surpassing human farming timelines. While humans began farming around 10,000 years ago, fossils reveal that termites were farming fungus as far back as 25 million years ago. Macrotermitine termites cultivate fungus crops in a way that closely resembles the farming practices of leaf cutter ants.
Termites don’t carry large chunks of leaves to grow their crops. Instead, they drop chewed-up pieces of plant matter, such as leaves and wood, which they cannot eat. These pre-chewed pellets serve as the perfect ground for fungal spores to grow into large mushrooms.
As the fungus matures, it breaks down cellulose and lignin—materials the termites are unable to digest—into nutrient-rich compost. This process provides termites with two sources of food: the mushrooms they eat and the compost they consume for nourishment.
By cultivating fungus within their nests, termites can thrive in arid environments, as they have a reliable food supply secured within the mound. As the fungus decomposes plant material that termites cannot digest, it also enhances the nutritional value of the surrounding vegetation, allowing termites to extract more sustenance from their environment.
7. Ambrosia Beetles
Ambrosia beetles belong to the weevil family, with thousands of species found around the world. These beetles get their name from their food source—ambrosia, a term meaning 'food of the gods.' However, the ‘ambrosia’ these beetles consume is actually a type of fungus.
Ambrosia beetles burrow into tree wood to create tunnels where they raise their larvae and cultivate their fungal crop. Throughout their development, they rely exclusively on this fungus for nourishment. Adult beetles in a colony manage the fungus, trimming it to encourage growth. When it's time to change trees, the beetles use a special organ called mycangia to carry and preserve the fungus while transporting it.
6. Littorina Snails
Shifting focus from sophisticated farming practices to a more basic form of food sourcing, let’s explore the Littorina snail. This marsh periwinkle feeds on fungus, but to create abundant fields of food, they first take a risky step. These snails venture above the water, where they are more vulnerable to predators, to munch on blades of swamp grass. While this grass offers little nutrition, and being in the open air is hazardous, this action is a short-term challenge for long-term rewards.
The swamp grass, once damaged and fertilized by snail waste, provides the ideal conditions for fungus to thrive. This fungus holds a much higher nutritional value for the Littorina snails. Unlike more labor-intensive methods of cultivation, this form of farming is more passive but effective in allowing the snails to optimize their food supply.
5. The Owl Limpet
The owl limpet is the largest limpet species in North America, reaching up to 4 inches (10cm) in length. These small mollusks are highly territorial and protect their algae gardens by forcefully ramming intruders off the rocks. Their homes are crucial as they carefully tend to and harvest the algae that sustains them.
Owl limpets create and maintain an algae mat approximately 1 square foot (1,000 square centimeters) in size by secreting mucous. As they graze on their algae, they leave behind a slimy trail that encourages further growth. They remain close to their homes, as retracing their mucous paths ensures a fertile environment for their gardens.
It takes about three weeks for an owl limpet to establish a thriving farm in a barren environment. However, if the limpet is removed, the ecosystem suffers drastically, as other algae eaters will consume the entire garden in just two weeks, leaving it barren. An owl limpet can maintain the same garden for approximately four years through periodic feeding and mucous secretion.
It’s important to note that only female owl limpets engage in this farming behavior. In contrast, the males are opportunistic feeders who often raid the farms of females until they are driven away by force.
4. Damselfish
Longfin damselfish are remarkable farmers. Not only do they tend to their crops, but they also domesticate shrimp to help fertilize their farms.
Damselfish are limited in their diet, as their digestive systems cannot handle fibrous foods. To ensure they have a steady food supply, they establish territories where they carefully remove unwanted algae, allowing their preferred crop to thrive. In many areas, the algae they consume are only found within these managed farms. Without the damselfish’s influence, other algae species would overtake and outcompete them.
To safeguard their farms, damselfish are quick to drive off any intruders, except for one small zooplankton—mysid shrimp. These shrimp are vital for the algae’s growth as they reside in the farms where they are protected from predators. While safe, the shrimp contribute by depositing waste, which enriches the algae. Studies comparing damselfish farms with and without shrimp swarms have shown that the presence of shrimp leads to higher-quality algae.
3. Pocket Gophers
At first glance, one might think humans are the only mammals to practice farming. However, the final example in this list reveals otherwise. These industrious burrowing rodents, pocket gophers, farm roots in their tunnels to provide up to 60% of their diet.
Digging tunnels requires significant energy, and pocket gophers have developed a method to ensure a steady food supply by selectively cropping and fertilizing roots in their tunnels. While they don’t plant their own food, their behavior fosters the growth and spread of these root crops.
The environment inside pocket gopher tunnels is humid, and the soil is enriched with nutrients from gopher waste. This creates an ideal setting for the nearby roots to thrive. The gophers harvest these roots, which further stimulates their growth.
2. Yeti Crabs
Deep in the ocean, scientists have discovered crabs with large, shaggy arms, reminiscent of the limbs of the abominable snowman. These unique arms aren't just for show—they play a vital role. Yeti crabs cultivate bacteria on their hairy claws, ensuring a steady food source for themselves.
Unlike other creatures such as deep-sea shrimp, which rely on bacteria growing on their bodies for nourishment, yeti crabs take a different approach. They actively farm the bacteria by waving their claws over fluids released from hydrothermal vents or methane vents deep in the ocean. This motion provides nutrients to the bacteria in a sunless environment, and without the crabs' rhythmic movements, the bacteria would run out of essential gases like methane or oxygen.
The yeti crab collects its bacterial harvest by using specialized hairs around its mouth to scrape the bacteria off its claws.
1. Upside-Down Jellyfish
Known by various names, the Cassiopea jellyfish is most famous for its peculiar behavior of resting upside down. Unlike many jellyfish, the spotted variety doesn't swim much. Instead, it cultivates algae (zooxanthellae) inside its body. By flipping over, the jellyfish exposes its underside to sunlight, which is vital for the algae to photosynthesize and provide nourishment.
For many species, this algae farm accounts for the bulk of their nutrition. However, about 10 to 30% of the jellyfish's diet still comes from capturing food using its tentacles. It stuns zooplankton with stinging cells and then moves the immobilized prey toward its mouth.
