ath ▁is ▁shed ▁following ▁ing estion , ▁at ▁which ▁point ▁the ▁lar va e ▁short en ▁slightly ▁and ▁measure ▁ 3 7 6 – 5 4 0   µ m ▁in ▁length . ▁After ▁ 2 4 ▁hours ▁after ▁ing estion , ▁lar va e ▁in va de ▁the ▁m uc os al ▁layer ▁of ▁the ▁int est ine . ▁Ar ound ▁ 4 ▁days ▁after ▁ing estion , ▁L 3 ▁mou lt ▁into ▁L 4 ▁in ▁the ▁subm uc osa ▁of ▁the ▁int est ine . ▁At ▁ 6 ▁days ▁after ▁ing estion , ▁they ▁enc yst ▁in ▁the ▁mus cle ▁layer ▁of ▁the ▁int est ine ▁and ▁start ▁m aturing ▁in ▁to ▁adult ▁par as ites . ▁By ▁day ▁ 1 4 , ▁adult ▁male ▁and ▁female ▁w orm s ▁contact ▁in ▁the ▁l umen ▁of ▁the ▁int est ine , ▁mate , ▁and ▁produce ▁eggs ▁that ▁are ▁passed ▁in ▁the ▁fa ec es , ▁thus ▁continu ing ▁the ▁lif ecycle . ▁Ad ult ▁males ▁are ▁tight ly ▁co iled ▁and ▁usually ▁measure ▁ 8 – 1 0   mm ▁in ▁length . ▁The ▁females ▁are ▁also ▁tight ly ▁co iled , ▁but ▁larger , ▁meas uring ▁ 1 8 – 2 1 mm ▁in ▁length . ▁Ad ult s ▁are ▁character ized ▁by ▁a ▁dark ▁red ▁p ig ment ation , ▁whereas ▁the ▁free - l iving ▁lar val ▁forms ▁are ▁mostly ▁transl uc ent . ▁ ▁Ep ide mi ology ▁ ▁In ▁natural ▁in fe ctions , ▁H .