spidey
Explanation
The comic presents a conversation between two people where one shares escalating facts. First: "Did you know that much of household dust is dead human skin cells?" The other responds with a calm "OK." Then: "And did you know it's estimated that billions of spiders live near humans?" Another calm "OK?" Then the first person connects the dots: "And so spiders likely ingest a teeny bit of human. Let's say it's 0.001 grams per day, in which case--" The other person's eyes go wide: "OH. MY. GOD." The caption below reads: "Household spiders consume approximately one human every three months."
This comic is a riff on the famous (and false) internet factoid that "you swallow eight spiders a year in your sleep." Weinersmith inverts the premise entirely: instead of humans accidentally eating spiders, spiders are accidentally eating humans -- in the form of skin-cell-laden dust. The joke works by taking individually true or plausible facts (dust contains skin cells, spiders are everywhere, spiders inadvertently consume dust) and chaining them together with back-of-the-envelope math into a horrifying-sounding conclusion. The punchline -- "one human every three months" -- is presented with deadpan scientific authority, mimicking the style of pop-science factoids that circulate online. The humor lies in the absurdity of aggregation: the idea that spiders are collectively "consuming" a human is technically a valid way to frame the arithmetic, but it makes something utterly mundane sound like a horror movie premise.