Tzod (Trapping) - Breaking Down the 39 Melachot

You're enjoying a snack outside  on a beautiful Shabbat afternoon,   and there's a fly that is bothering you and  going on your food. Are you allowed to take   a cup and to trap the fly so it won't bother  you anymore? One of the melachot of Shabbat   is the melacha of Tzod, which means trapping,  and therefore you are not allowed to trap a   fly on Shabbat. However, if it's a bee or a  wasp or a hornet that's flying around you,   and they are easily agitated, and if they  sting you, it will cause you significant pain,   you are allowed to trap it in  order to keep it away from you.