What feature do all spiders have in common?

All spiders produce silk, which is a defining characteristic of the class Arachnida to which they belong. This ability to produce silk is essential for various functions, including building webs for trapping prey, creating egg sacs, and aiding in mobility (such as ballooning, where they use silk threads to ride on the wind). The silk production mechanism is vital for their survival and has evolved to assist in hunting and reproduction.

The other options do not accurately describe features that are common to all spiders. For example, not all spiders can fly, as flying is primarily associated with insects. Spiders also do not have wings; instead, they have eight legs and no wings at all. Additionally, while some spiders may have bright colors, many are actually quite dull or camouflaged. Thus, the ability to produce silk remains the universal feature among all spiders.