Such are the examples We cite for the people, but none reason except the knowledgeable.
Translation endnotes
[29:41-43] The example is interesting. The spider is not the male one (ankab), but a female one (ankabut). Thus, it might be referring to spiders like the Black Widow that eats their males after having an intimate relationship. (The grammatical structure of the verse is similar to that of 40:20).