The name of the 29th Surah of the Quran is Al-Ankabut (the spider) as the insect has been mentioned in verse 41 of the chapter.
In this verse, disbelievers’ idolatry is compared to relying on a spider’s web: “The likeness of those who have taken guardians, other than Allah, is as the likeness of the spider that takes to itself a house; surely the spider's house is the weakest house if they but knew.”
It is said in the interpretation of this verse that the comparison aims to show that worshipping idols has no benefit for disbelievers and cannot save them from harms and hardships.
The first part of the Surah is about the issue of divine test and the status of Munafiqeen (the hypocrite). These two issues are related because knowing the hypocrite is not possible without testing them.
Another part of the chapter discusses Tawheed (monotheism) and the signs of God in the world as well as fighting Shirk (polytheism).
The last part of Surah Al-Ankabut elaborates on the weakness and inability of fake deities and idols, saying that they are firm and hard in appearance but are incapable of solving problems. It also talks about the greatness of the Quran and the truthfulness of the Holy Prophet (PBUH).