I am not sure about this one but zigzag Spiders do hang upside down and do usually not have a hole to stay in also the are none as "the black and yellow Argiope"The Black and Yellow Argiope
Gymnastics is kind of an upside down sport because the handstand you do it upside down and that's the only sport you do upside down flips and etc...
The worst kind.
they get a headache from hanging upside down
Inversion.
could be a male crab spider, or a writing spider.
there is no particular reason that your cat fish swims upside down but it could just be the kind of cat fish you have. it isn't abnormal for a cat fish to swim upside down because some can only swim that way.
It would be theoretically possible, but kind of pointless.
It starts with cap!
The Trapdoor spider eats insects grasshoppers Beatles and any bug silly enough to come to close to their hole.
A convex lens
U no offense, but kind of obvious.
Answerswims NooN