Lub thav duab ntawm qhov ntsuas no yog ua los ntawm cov hlau .Nws cov qauv zoo nkauj, thiab nws muaj covqhov zoo ntawm cov ntim me me, qhov hnyav tsawg, muaj peev xwm loj, tsis tshua muaj suab nrov, kev ua haujlwm siab thiabyog li ntawd. Nws tuaj yeem siv rau hauv tsev kho mob thiab chaw kuaj mob biochemical rau kev soj ntsuam zoo ntawmntshav, urea thiab ntshav.