YOU SAID:

I hear their menstruation attracts bears.

INTO JAPANESE

彼らの月経が熊を引き付けるのが聞こえます。

BACK INTO ENGLISH

I hear their menstruation attract bears.

INTO JAPANESE

彼らの月経は熊を引き付けると聞いています。

BACK INTO ENGLISH

I heard that their menstruation attracts bears.

INTO JAPANESE

彼らの月経は熊を引き付けると聞いた。

BACK INTO ENGLISH

I heard that their menstruation attracts bears.