Do spiders fart

Answer 1

YES-

All animals that go through the process of digestion-including Spiders- produce gas as a by product of cellular respiration and therefore must -Fart or release the gas somehow-

Since spiders have a completely different digestive system as humans (and also breathe with booklungs and spiracles) they do not release gas the same way we do- through the mouth (burp) and anus (fart)

IN ADDITION,

Spiders force enzymes from their 'mouth' into the hole they made in the prey,

then suck it back into the mouth. They repeat this action-A back and forth flowing repetition of enzymes over and and over- so there is a high possibility that air bubbles may be caught in this liquid exchange

Are they smelly?

that is a different story -probably yes but it's too slight/small quantity for us to detect.