YOU SAID:

A bird stole my hot dog while I was at a picnic

INTO JAPANESE

私がピクニックをしているときに鳥が私のホットドッグを盗んだ

BACK INTO ENGLISH

A bird stole my hot dog while I was having a picnic

INTO JAPANESE

ピクニック中に鳥がホットドッグを盗んだ

BACK INTO ENGLISH

A bird stole a hot dog during a picnic

INTO JAPANESE

ピクニック中に鳥がホットドッグを盗んだ

BACK INTO ENGLISH

A bird stole a hot dog during a picnic