http://revach.net/article.php?id=2052

Section: Parshas HaShavua   Category: Quick Vort
Parshas Shemini: Rav Chaim Kanievsky The Difference Between a Chasid and a Mouse
One of the unkosher birds listed in Parshas Shemini (11:19) is the “Chasida”, the stork.  Rashi says that it is called Chasida from the word “Chasid”, pious.  The stork does Chesed with its friends and it shares its food source rather than hoard it for itself.  When it comes to the mouse however, the Yerushalmi (Bava Metzia 3:5) describes it as a “Rasha” because it not only eats the homeowner’s food it also calls its friends to eat.  Why the unbalanced treatment between the two of these generous creatures?

Rav Chaim Kanievsky answers that the Chasida’s food comes from Hefker it is not taking from anyone else.  However the mouse steals his food from people’s homes.  He says that from here we learn an important lesson.  If you do Chesed on on your own expense then you are a chasid, but on someone else’s expense you are a wicked mouse. (Derech Sicha)