Don't think of it that way. These arachnids are incredible creatures.
We all know from the movie Spiderman that spiders are lethal and have amazing physical abilities. Jumping spiders, for example, can jump several times the length of their body. The silk they produce is stronger than steel and tougher than Kevlar. A thread with a radius of 3-cm can stop a Boeing 747 in full flight. And tiny spiders have brains so huge the neurons spill into their legs.
|Horizontal sections of several spider species showing extension of neurons (black arrows) into leg joints in tiny individuals. |
Image: R. Quesada et al. , Arthropod Structure & Development, 40 (2011) 521-529
Given the huge brain size, why are they not the dominant species on Earth?
For biology-majors, you have probably heard of Haller's rule, which holds that the brains of smaller animals are larger relative to body size than large-bodied forms. Well this is a classic case of animals adhering to the rule. Human beings do not have the heaviest brains in overall weight, or even weight in proportion to their bodies, but our brains appreciate humor, beauty, death, and many more, whereas animal behaviors are driven largely by instinct.
The power of contemplation only exists in the minds of human and some highly intelligent animals--well at least that's what scientists found so far.
Size doesn't matter; it's the way the brains work that does.
But still, whenever you choose to smack a tiny spider, remember that it is way brainier than you can ever be.
R. Quesada et al. , Arthropod Structure & Development, 40 (2011) 521-52