Dear Laura,
    Just a thought...maybe Tribble is using combination of other senses to
chase Trella and find waste basket etc..  She can probably hear, feel
(feet feel vibrations in floor, whiskers and hair sense air disturbances),
smell, and perhaps see shadows to some extent?  and maybe memory plays a
part in finding the wastebasket, too.:) Is she diabetic?  Best wishes,
Kari Lee Class of 1999, Tufts Vet School
[Posted in FML issue 1181]