50 Facts About Caterpillars


Before a butterfly can spread its colourful wings, it starts life as a humble caterpillar! It’s easy to mistake the puny caterpillar for a worm with its elongated body and numerous legs, but it’s actually a growing transforming insect that has a complete exoskeleton. If you want to know more about this little crawley, read on to learn 50 facts about Caterpillars.   

Fact 1: Caterpillars are insects, not worms. 

  • Caterpillars are insects, just like their parents: butterflies or moths.

Fact 2: A common butterfly in Britain is the Painted Lady, who can be seen anywhere that’s dry and open.

  • Britain is also home to the Speckled Wood butterfly and the Holly Blue butterfly, but there are many more to be seen and can be read about on conservation websites.

Fact 3: Female butterflies lay their eggs either singly or in batches, on or near food plants that will be used by the caterpillars.

  • As soon as the eggs hatch, the tiny caterpillars go straight to the food and eat as much as they can for 10-12 days. 

Fact 4: Females lay eggs 5 to 7 days after emerging from the chrysalis.

  • The eggs then hatch into caterpillars after three days.

Fact 5: Adult butterflies emerge from the chrysalids after 7 to 10 days. 

  • They then mate as soon as possible, since butterflies only live a month on average. 

Fact 6: Only 1 or 2 caterpillars grow up to be fully grown adults. 

  • There are many diseases and parasites that kill caterpillars, including viral, protozoan, fungal, and bacterial infections, as well as predators like birds or larger insects.  

Fact 7: Caterpillars are born extremely small.

  •  But they start growing and expanding as they start eating.

Fact 8: Caterpillars moult their skin as they grow.

  • Since a caterpillar’s exoskeleton does not stretch or grow, it has to shed its outgrown skin several times. 

Fact 9: During the feeding and growth stage, a caterpillar doesn’t stray far from its ‘food plant’, the caterpillar also sleeps under the ‘food plant’s’ leaves at night. 

  • However, when it’s ready for pupation, a full-grown caterpillar will wander off some distance from its ‘food plant’ to find a good place to make its chrysalis.

Fact 10: A caterpillar’s brand new exoskeleton, after it has moulted, is called “prepupa”.

  • Just before entering the pupal stage, the caterpillar expels whatever is in its gut. 

Fact 11: Caterpillars are voracious feeders.

  • In fact, many of them are listed as one of the most notorious agricultural pests. 

Fact 12: The caterpillar will go through the pupal phase, which is where they form a cocoon or chrysalis, before emerging as an adult butterfly. 

  • The whole process from starting out as an egg to becoming a butterfly is called metamorphosis. 

Fact 13: Moths also start out as caterpillars.

  • But instead of forming a chrysalis, moths make cocoons from which they emerge as fully grown moths with wings.

Fact 14: Most caterpillars have 8 pairs of legs— 3 pairs of true legs and 5 pairs of prolegs in the abdomen.

  • However, the caterpillars of some tiny leaf-mining moths may have no legs at all.

Fact 15: Caterpillars have 6 pairs of ‘simple eyes’ or ocelli.

  • Although their simple eyes can detect changes in light intensity, they cannot form an image.

Fact 16: The plants that caterpillars eat are called host plants. 

  •  While the plants that adult butterflies drink nectar from are called nectar plants.

Fact 17: Caterpillars, surprisingly, have up to 4,000 muscles in their tiny body. 

  • That’s an incredible feat in comparison to the number of muscles we humans have (we have around 629). 

Fact 18: Some caterpillars can consume 27,000 times their body weight during their larval stage! 

  • While humans on average will only consume 14 times their normal body weight per year. 

Fact 19: Caterpillars are members of the ‘Lepidoptera order’.

  • Members of this insect order include moths and butterflies. 

Fact 20: Caterpillars are considered as agricultural pests and can be economically draining for farmers. 

  • In fact, more caterpillar species are known by farmers in comparison to butterfly species’ because of the damage they cause to fruits and other agricultural produces.

Fact 21: Caterpillars breathe through a series of small openings called spiracles found along the sides of their thorax and abdomen.  

  • To breath, a caterpillar contracts its muscles to open and close the spiracles.

Fact 22: A few caterpillars of the family ‘Pyralidae’ can actually breathe underwater. 

  • For instance, the brightly-coloured Hawaiian Hyposmocoma moth has a unique evolutionary trait: it can live half its life underwater. 

Fact 23: On average, a caterpillar has 248 muscles in its head segment alone.

  • A caterpillar moves by contracting its muscles in the rear segments, pushing blood forward into the front segments, which then elongate the torso. 

Fact 24: Caterpillars are equipped with a short antennae to help them find food. 

  • Sawfly larvae differ from true caterpillars in this respect, since they have prominent ocelli on the head capsule. 

Fact 25: They can detect vibrations, often at a high frequency. 

  •  A small group of researchers from Canada and Brazil found out that one species of caterpillar use vibrations to attract other caterpillars. 

Fact 26: Caterpillars of the common hook-tip moth ‘Drepana arcuata’ can produce sounds.

  • This moth species creates sounds in order to defend their silk nests from members of their own species. 

Fact 27: The origins of the word “caterpillar” date back to the early 16th century. 

  • They derive from Middle English “catirpel” and “catirpeller” which is probably an alteration of Old North French “catepelose”.

Fact 28: A caterpillar’s jaw is specifically designed for chewing leaves. 

  • Its mandibles are quite sharp and tough. 

Fact 29: Caterpillars are not only rich in protein, but they’re also a great source of minerals and vitamins. 

  • Depending on the species, caterpillars are rich in minerals such as potassium, calcium, magnesium, zinc, phosphorus and iron.

Fact 30: Caterpillars can sometimes resemble their host plant. 

  • They may even plants have parts that mimic plant parts such as thorns.

Fact 31: Birds love to snack on caterpillars every now and then.

  • Some birds, like cuckoos, will even swallow the hairiest of caterpillars.

Fact 32: A caterpillar’s most aggressive defence mechanism against predators is its bristles, that can come with venom glands called urticating hairs.

  • Some urticating hairs can cause extreme itching, skin irritations and damage to eyes and the respiratory system.

Fact 33: Some caterpillars regurgitate acidic digestive juices as a defence mechanism against attackers. 

  • However, a caterpillar is less likely to vomit on its predators when in groups than when alone. 

Fact 34: Some caterpillars obtain protection by associating themselves with ants.

  • In doing so, ants protect themselves against potential predators as well.

Fact 35: Caterpillars are primarily nocturnal in nature. 

  • They come out at night to feed on the leaves of any plants they find in the area, or other food sources that they are accustomed to consuming.

Fact 36: The most economically draining caterpillar is the Cotton Bollworm. 

  • The Cotton Bollworm often punctures greens and allows rot and infection to set into the plant – thus making the plant useless. 

Fact 37: In some cases, caterpillars can be bad for humans.

  • Issues for humans range from urticarial dermatitis and atopic asthma to osteochondritis, consumption coagulopathy, renal failure, and intracerebral haemorrhage. 

Fact 38: A caterpillar’s urticating hairs have also been known to cause keratoconjunctivitis.

  • This condition results in the inflammation of the cornea and conjunctiva.

Fact 39: Male butterflies usually die after mating. 

  • Interestingly, male butterflies are ready to mate just an hour after emerging from the pupa.

Fact 40: Caterpillar eggs can come in many shapes and colours.

  • Egg shapes include spherical, oval, and pod-shapes, while the colours include white, green, and yellow.

Fact 41: Newly hatched caterpillars are called ‘larvae’

  •  The larval stage of the butterfly’s life cycle is a time for growth.

Fact 42: A varied diet can be dangerous for caterpillars. 

  • Wesleyan University and UC Irvine biologists found out that caterpillars who eat no more than two plant species hide more effectively from bird predators, in comparison those caterpillars that ate a variety of foods were not able to hide as well from predators.

Fact 43: When a caterpillar starts munching on a tobacco plant, the plant sends out a chemical distress call that attracts predators of the caterpillar. 

  • For instance, the wild tobacco plant can identify a hornworm caterpillar by its saliva. 

Fact 44: “Zombie” Caterpillars are a butterfly or moth larvae that have been infected with a virus. 

  • The virus causes them to climb to the treetops to die, at the top of the tree they liquefy and rain on the foliage below to infect others.

Fact 45: Caterpillars form “processions” of up to 300 insects in a row.

  • This is a clever strategy that makes it hard for predators to pick them up from the line.  

Fact 46: The Saddle-Back caterpillar brandishes a pair of fleshy ‘horns’ covered with venom-secreting hairs.

  • Its hairs can cause stinging, swelling and a nasty rash when touched. 

Fact 47: The Woolly Bear caterpillar has the longest life cycle. 

  • It is best known for its slow rate of development, as its full caterpillar life cycle may extend up to 15 years. 

Fact 48: The Mycalesis Perseoides butterfly in its larval form resembles a cat’s face. 

  • With its rounded horns and fuzzy face, the insect has been compared to Hello Kitty. 

Fact 49: The European Pied Flycatcher is one species that preys upon caterpillars. 

  • The flycatcher typically finds caterpillars among oak foliage.

Fact 50: Caterpillars are often used as metaphors for life.

  • In the Christian faith, caterpillars are associated with resurrection and rebirth, while others say that the little caterpillar symbolises great hope and endurance.

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