There are more things in the heavens and on earth, Bereishit, than are dreamt of in your philosophy.
"Many plants use birds to disperse their seeds. Birds eat the fruits, move away from the plant, and then poop, depositing the plant’s seeds in a new location. When insects are eaten it is assumed that they and their unborn young don’t survive, but a team of researchers wondered whether a similar mechanism helps insects transport their offspring long distances. Stick insects make eggs that have a very hard shell, which can survive acidic environments, such as those in bird guts."
I would imagine that in third world countries people eat seeds, then go into the fields to relieve themselves and ...voila...plants are moved to a new place.
Depends on the toughness of the seed's outer layer - tomato seeds, for example, can pass through the gut intact.
Spread those tomatoes all around....they're healthy.@moNOtheist