Midrasch zu Wajikra 11:23

6) If they are mentioned above, why are they mentioned below? (i.e., Why mention here "All who touch their carcass will be unclean until the evening. And he that carries their carcass shall wash, etc.", if this has already been stated above [Vayikra 11:23-24])? What is stated above speaks of ever min hechai, and what is stated below speaks of ever min hameth (even if it lacks an olive-size of meat. [For if it has an olive-size of meat, it is tamei in any event by reason of an olive-size of neveilah]). (Why is a verse necessary for this?) Does it not follow a fortiori? viz.: If ever min hechai, where meat that falls from it (a living animal) is clean, confers tumah, then ever min hameth, where meat that falls from it (a dead animal) is tamei, how much more so should it confer tumah? — No, this may be so in the case of ever min hechai, the prohibition of which obtains with the sons of Noach as it does with Israelites. Would you say the same for ever min hameth, the prohibition of which does not obtain with the sons of Noach as it does with Israelites? Since this is so, (we would say that) it should not confer tumah. It must, therefore, be written "one who touches" and "one who carries" to include ever min hameth (as conferring tumah).

10) Rabbi says (Vayikra 11:23): "And every creeping thing that flies, which has four legs; it is detestable to you" — If it has five legs, it is clean. "it is detestable" — to exclude their admixture. From here the sages ruled: Unclean grasshoppers which were pickled together with clean ones do not render their (common) brine unfit. R. Tzadok testified about the brine of unclean grasshoppers that it (itself) is clean.