Umwanya wubwiherero ni muto, kandi guhuza nabyo ni ngombwa cyane, kubera aho bigarukira, kandi igikarabiro nigice cyingenzi cyubwiherero.Niba ubwiherero bufite ibikoresho byo mu bwiherero.Kubera ingano nini nibisabwa cyane kugirango ushyireho, urukuta rugomba gutoborwa.Ku ngo nto, umwanya ni muto cyane.Niba inkingi yubwoko bwo gukaraba ikoreshwa.Ingano ntoya yinkingi ibase ni byiza.Ikibase gihagaze ku buntu kirasa ku bushyuhe bwo hejuru, budahisha umwanda kandi byoroshye koza.Ntutinye ubushuhe.