Dickinson opens with a joke that isn't quite funny. To say a life was so small it "would have starved a Gnat" makes the tiniest creature imaginable the yardstick, and then finds even that too generous. The speaker, though, was "a living Child", and the "yet" in that line pushes back. She was small, but she was alive, and so she was hungry. The poem sets a tiny body against an enormous need, and it ends with the humbling discovery that a gnat, of all things, is the mightier of the two.
The imagery of hunger is startlingly physical. Need is not something the child feels inside her. It sits "Upon me -- like a Claw", a predator on her back. The next comparisons make it worse. She can no more remove it than "coax a Leech away", and "coax" is a gentle, nursery word for a gentle method that obviously fails. A leech clings and feeds on its host, so the image makes her own appetite sound parasitic. Then comes the "Dragon", and the scale lurches from gnat to monster within a single stanza. The child is trapped between the minuscule and the mythic, too small to matter and too weak to shift what presses on her. The rhyme of "remove" with "move" ends the stanza on the same helplessness twice.
The third stanza explains why the gnat is the better-off creature. It has "The privilege to fly / And seek a Dinner for myself". Calling flight a "privilege" turns an ordinary ability into a mark of rank, which is how it must look to someone who cannot feed herself. "Dinner" is a cosy, domestic word set among claws and dragons, and the clash is part of the poem's dark comedy. The gnat also gains a capital letter: "How mightier He -- than I". Dickinson capitalises many nouns, but here the capital works almost like a title of respect. Power is not measured by size. It belongs to whoever can go and get their own food.
The last stanza is the hardest, and it can be read more than one way. The gnat has the "Art / Upon the Window Pane / To gad my little Being out -- / And not begin -- again --". One reading is that the gnat can flit and batter itself against the glass until its small life is spent, and then be finished. "Gad" means to wander restlessly, so the gnat's pointless buzzing becomes both freedom and an exit. The child has neither. "Art" is a bitter choice of word, since even ending a life becomes a skill she lacks. The closing dash leaves "again" hanging, and it is tempting to hear hunger itself in it, a need that begins again every time it is met. That is an inference, but the unfinished punctuation invites it.
The form holds all this in tight control. Each stanza runs six syllables, six, eight, six, a hymn-like pattern with the third line stretching out like a breath before the short final line closes it. Only the second and fourth lines rhyme, and loosely. "I" and "necessity" meet more by the ear's goodwill than by true rhyme, and "Pane" and "again" match only if you pronounce "again" to rhyme with it. The pronoun "I" keeps landing at line ends, in stanzas one and three, a small word in a position of weight, as if the speaker were insisting on being counted. The past tense also matters. She speaks of having been a child, which suggests a voice looking back with calm, almost dry composure rather than crying out in the moment.
That composure is much of what makes the poem significant. Dickinson, who lived in Amherst, Massachusetts, and saw most of her poems published only after her death, often changes the scale of the world, and here she does it to dependence itself. She does not ask for pity. She measures, comparing the child with a gnat, a leech and a dragon, and by the end the comparison has turned into a quiet verdict. The most helpless human stage, infancy, is placed below an insect on the scale of power, and the poem leaves that judgement standing without softening it.