Two people are lingering in bed well past a normal waking hour, and the speaker is completely content. The poem gives us just a few small images: the time, "8:00"; a hand compared to a vine, creeping and curling along; and a partner's hips, "ready," which hints at desire and invitation without spelling anything out. The vine image makes the touch feel slow and natural, as if the hand is growing toward her rather than reaching on purpose.
The last two lines turn from body to mind. The speaker says there's "no good reason to try / thinking anything," and it reads like relief. Thought is simply set aside. The title, "Even educated fleas," seems to nod to the idea that even clever creatures give in to instinct, though the poem doesn't explain it, so that's a guess from the text. The mood is warm, drowsy, and a little playful. Nothing needs solving, and the speaker is happy to let the body lead.