When you look at a caterpillar, even if it’s up close, it’s hard to figure out how many eyes it has as caterpillars aren’t really big, and their heads are even tinier. So, do caterpillars have eyes? And, if they do, how many eyes does a caterpillar have?
Caterpillars usually have six eyes on either side of their heads, making 10, 12, or 14 total eyes. These eyes are called ocelli or stemmata.
Compound eyes that moths, butterflies, and flies have are made up of several smaller eyes called ommatidia. But, these aren’t found in caterpillars.
Caterpillars have simple eyes, and they come in varying numbers. Their stemmata or ocelli are usually 5 to 7 in number on each side of their head.
You could think that a caterpillar’s eyesight would be excellent with such variety in eyes. However, this is not the case, as even with several eyes, the most a caterpillar can decipher is darkness from light.
Caterpillar eyes can’t make out shapes and can only tell the differences between daytime and night.
Where are the 12 Eyes of the Caterpillar?
The 12 (although it can be 10 or 14) eyes that varying species of caterpillars have are located below the antennae arranged in the form of a circle. They’re above the mandibles.
These eyes, antennae, and mandibles are located on their tiny heads, on the frontal end of their long cylindrical segmented bodies.
Their head has the eyes, mandibles, and antennae, their thorax has their legs, and their abdomen has prolegs which are fleshy stumps used to grab onto various surfaces like branches and twigs. Prolegs aren’t actual legs.
How Many Eyes Does a Butterfly Have?
Butterflies have two eyes like us, but their eyes aren’t ordinary. They’re compound eyes and are made up of 12,000 individual cells. These cells or lenses allow them to see varying things in different directions simultaneously, and it greatly helps when they’re flying.
These eyes also allow them to see ultraviolet rays, which are invisible to us but are necessary for them to see so they can find flowers. Their brains collect all the information the compound eyes receive and make one picture from all those tiny individual parts that each specific lens receives.
Butterflies are known to have one of the widest ranges in vision compared to many other living organisms. Their visual field is larger and wider than humans, and their visual perception of fast-moving objects is also amazing.
Their eyes form a wider picture that covers almost 360 degrees of sight, besides the blind spot of their bodies. The reason for their wide range of sight is their compound eyes are a multifaceted array of varying eyes altogether arranged to form two larger compound eyes.
How Do Butterflies See Ultraviolet Light?
Butterfly compound eyes are able to see wavelengths that an ordinary human eye is unable to see. Butterfly compound eyes can see light wavelengths ranging from 254 to 600nm. This range has ultraviolet light in it. Human eyesight can see wavelengths from 450 to 700nm.
Flicker rate is something that also differs greatly among butterflies compared to other living things, including us. Flicker rate can be defined as the frame rate at which each image goes by on your TV screen to make a video.
The human flicker fusion rate ranges from 45 to 53 flickers each second. Butterflies have a flicker fusion rate that is 250 times more powerful and faster than that of a human and other animals. This gives them an amazing consistent updating image.
What are Fake eyes on Caterpillars?
There are patterns on the bodies of some caterpillars that aren’t actual eyes but look like big staring eyes. These are the defensive mechanisms on certain types of caterpillars and some butterflies and moths as well to scare off predators from eating them.
These eyes are called fake eyes, and they’re located on the thorax of the caterpillar, and in the case of a butterfly or moth, they’re located on the wings. The eyes are highly noticeable, but the caterpillar itself is harmless as the eyes serve the purpose of only being defensive mechanisms for the insects.
Summary
A caterpillar has simple eyes called ocelli or stemmata, which are light-sensitive eyes and are either 4, 5, or 6 on either side, meaning a caterpillar has either 10, 12, or 14 eyes in total.
The several eyes don’t really have good eyesight. They’re sensitive to light and only fulfil the purpose of distinguishing light from dark and dark from light.
