Don't recall ever seeing or evidence of rats around our place for 30 years. That was until the new neighbours out the back moved in. With them came their dog, that was OK, Dolly the lamb, but that only made it to Christmas, chooks, still around, and an open compost heap that they still keep going. Now we got 20 odd Indian Myna birds, no i won't call them common myna to be politically correct. And rats most of the time, even been in my roof space. Now both side neighbours and I grow vegetables and fruits, but one neighbour have been doing it for decades and complains to me that now he has rat problems. All 3 of us have seen and trapped plenty of rats. Forget birds eating your crop, try stopping the rats. I got 8 this year in my back garden beds so far.