The speaker is holding a tiny bumblebee in their hand. The bee is so light it hardly seems to be there, and it seems too tired or weak to fly, so it falls asleep in the warmth of the speaker's palm. The speaker talks to it gently, calling it "wee" and asking where it goes and what it thinks.
Those questions are never answered. Instead, the speaker imagines the bee somewhere far away, in an unknown land full of its favorite flowers. Judging by the way the poem shifts from the real moment to this dream, the bee may be dreaming, or it may have died and the speaker is picturing a kinder place for it. The poem doesn't say which.
The mood is tender, quiet and a little sad. The speaker feels protective and affectionate, and the final line, "And everything just silence," leaves a hush hanging over the whole scene, peaceful but also uncertain.