The poem begins with a single image: something trapped in amber, and the speaker seeing in it "my whole study." The word "stuck" in the title does double work. It means physically caught, like an insect in resin, but it also hints at feeling stuck in a life's work, a long and perhaps unfinished pursuit. The speaker seems to recognize himself in the preserved creature.
The phrase "one binding business" plays on the idea of being bound, held fast, and also on the work that binds a person to a single purpose. Whether that is a comfort or a trap is left open. Then evening arrives "to try / man and ant," and "try" can mean test, judge, or put on trial. The man and the ant are placed side by side, as if both are small figures facing the same fading light.
The mood is quiet, reflective, and a little wry. The poem suggests humility more than despair: a person looking at something tiny and finding a mirror.