Startled by a small creature on her hat, the speaker addresses a jumping spider directly, half-scolding it for the scare. Her camera had labelled it a cat, and the poem opens with that mix-up, then moves to the spider's many eyes and its hairy black-and-white body. She admits she almost bolted.
Curiosity takes over. She checks a spider book, learns the creature's name, and finds it "kind of cute," though she knows most people would disagree. The turning point comes with the facts: jumping spiders are harmless to humans and help get rid of mozzies and flies. The speaker says this information changed her life, which is a playful bit of exaggeration.
The mood is light, chatty and humorous, with simple rhymes that suit the friendly tone. Fear gives way to curiosity and then to kindness, and the poem ends with her choosing not to kill the spider and letting it stay on her window sill.