Animals (specifically corvids) don't measure things by weight and determine an exchange rate, they just look at them with a 1:1 ratio and check for similarity.
In this particular set up, they would simply correlate food with particular types of trash that they have been trained with and dump only those kinds of trash into the apparatus. To them, tearing up the trash would be more effort than finding new trash.
Animals (specifically corvids) don't measure things by weight and determine an exchange rate, they just look at them with a 1:1 ratio and check for similarity.
In this particular set up, they would simply correlate food with particular types of trash that they have been trained with and dump only those kinds of trash into the apparatus. To them, tearing up the trash would be more effort than finding new trash.