Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
nītēdŭla, ae, f., a kind of small red mouse, a dormouse, Cic. Sest. 33, 72: cf.: nitedula mus agrestis rubeus, Serv. ad Verg. G. 1, 181; Arn. 2, 47 (Hor. Ep. 1, 7, 29, the common read. is volpecula, but Bentley’s conjecture, nitedula, is adopted by Lachm. ad Lucr. p. 204, and by Haupt and Müll.; v. Orell. ad loc.).
The contr. collat. form nītēla, v. under nitella.