Spider climb vs Monstrous spider

[taliesin15]

RL spiders have trouble on smooth surfaces too. They can't even climb out of a bathtub without help! Why would you expect one to stick to a perfectly smooth, flat, featureless ceiling?

BUT, is the smooth surface *really* completely smooth? Does it have tiny motes of dust, grime, oily fingerprints and the like that we Medium-sized creatures have a hard time seeing without a magnifying glass and a bottle of Mr. Clean?

 

[Kmart Kommando]

Same with a black widows spider web (the jumbled mass). They don't follow radial patterns.

While a black widow's web does seem random, it is regular enough for me to recognize it when I see one, and know not to stick my hand near any dark or hidden places around it. Radial isn't the only spider web design though. The black widow's web is not randomly built, but is built to simulate the background flora and also to be structurally durable when an impact occurs, and still has the nonsticky support lines for the spider's travels, as well as an area off to one side like a duck blind, where the spider waits for prey.