How Many Eyes Does A Spider Have to Help It See? [size=0.857143]Jumping Spider eye close-up (Photo: Thomas Shahan Flicker sharing).
Spider Eye Counting The short answer, it depends. For those of you who don't like spiders, I can see that getting up close and personal enough to count their eyes might be a bit daunting, that's why I'm writing this blog post. Spiders are amazing, and diverse, as well as being very beneficial for you and local ecosystems. To understand their eyes you have to understand their lifestyle. Here's a quick primer:  [size=0.857143]This is a nursery web spider, and a web builder. It lacks the two large focal eyes of a hunting spider (Photo: Wiki Commons).
- There are two main types of spiders, hunting spiders and web weaving spiders. Depending on how they feed, their bodies and their eyes are different shapes and sizes.
- In general, web building spiders tend to have poor eyesight and rely very much on touch, vibration, and chemical cues to find their prey.
- Hunting spiders are the spiders that don't build webs, instead they either build traps in the ground or run around leaping on other insects and eating them. This is why you see spiders on the kitchen floor at night when you turn on the light and they scuttle off. You interrupted their "bug hunting."
- Spiders usually have eight or fewer eyes (some have six or less).
- Most web building spiders can't see well, instead they can detect changes in light and dark, which relates to their photoperiod (day/night) cues for web building.
- Some wandering or hunting spiders also don't have great vision, but they can pick up on rapid movement and light-dark changes.
- A few spiders can also detect polarized light, like bees and some birds, and they can use this ability to find prey. Some, like jumping spiders, can also see ultraviolet light.
- Hunting spiders that have very good eyesight, during the day, include wolf spiders, jumping spiders, bolas spiders, and net-casting spiders.
 [size=0.857143]The eye arrangement of this wolf spider is typical of hunting spiders, having eight eyes, with two rows, two primary eyes, and two eyes on top for 8 total
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Post time 6-7-2019 09:39 PM
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Post time 7-7-2019 12:10 AM
