Named after a common Italian children's song, and shot by Mario Bava, this second (surviving) film in Rossellini's series of documentary-essays on the lives of creatures employs the same kind of revelatory, Cocteau-esque narration that the director used in Undersea Fantasy [Fantasia sottomarina, 1938] to invite, here as there, a fairy-tale scenario to enter the images. The opening titles of Lively Teresa [La vispa Teresa, 1940] even seem to foreshadow Cocteau's later cinema...
A utopia: bugs and gastropods live in the vicinity of one another, and abundantly. A little girl, a human, has invaded their field and snatched a butterfly out of the air; she has it between her thumb and forefinger, pinched at the wings. And so: "Beetles, scarabs, weevils spread the word and all together cry help. [...] From every hidden forest corner reinforcements rush, and each urges the other to follow. [...] Ranks thicken. Warcamps form boldly." As Rossellini goes down to the level of the microcosmos, speed seems also to decrease, in illustration of the elastic and proportional relationship between space and time; as though this slowing-down, this act of pausing to magnify, could alone accelerate a harmony for all beings.
Throughout my life, I've known a practical parade of T(h)eresas; in first- or middle-name position, the appellation is recurrent enough to assume a mercurial, maybe mythical / maybe mystical, significance chez Keller. Funny that the "lively" one of Rossellini's film is presented as an almost exclusively static entity — but in apportioning this stasis across each shot that features Teresa, Rossellini reconceives his human as something from Planet Olympus, whose monumental grandeur alone (at the level of the insects' eyes and that of our own as spectators), never mind external action, emanates a challenge for the microcosmos.
Teresa can be said to be "lively," in fact, in only one shot: a long-shot of her entrance onto the scene of the dispute. But even then Teresa is fixed compositionally at the same spot within the frame, like some axiom, or axis. The camera pans in perfect synchronicity with her gambol / act-of-war.
Casus belli. The entire bug-kingdom bombards her white-bright shoes, which nonetheless remain immobile. No girl's feet actually fill them, of course; the result is as beautiful and surreal a sequence of images as Rossellini (oh, eminent "realist"!) has ever filmed. Over this segment flows Rossellini's narration: "No-one dares venture onto the girl's legs. The warm white skin disgusts everyone."
Tune in to Roberto Rossellini's India, matri bhumi  for the exciting conclusion!!!