Yes, we start to see, especially if we live in the bush, that it's almost impossible to live and support this body without beings dying for us. So we start to open out to the unsatisfactoriness of the cycle of birth and death. Opening to the unsatisfactoriness of the cycle of birth and death brings up a great deal of Compassion and inspires us to see that the craving for the body that keeps us trapped in this cycle is unsatisfactory. Because in order to support a body, it means other living beings die.
But in order to stop killing, the only really way we can do that according to Buddhism is to become enlightened. So actually, if we really open to this suffering of Samsara and the unsatisfactoriness of the cycle of birth and death, it can be a catalyst for the wish for enlightenment. And for the Compassionate motivation to arise, that if we're going to have a body and have to be a part of killing other living beings, to at least make our life useful rather than just delight in the cycle of suffering. We need to bring up a motivation to make our life useful and lessen some of the suffering. That is, to give something back to the world rather than continually delight in the suffering of other living beings, so that in the support of our body, we're at least trying to lessen suffering in the world.
"Unmindfully careless"? Yes, it brings up an urge to be more mindful in our life so we can lessen some of the suffering of other beings, so that our unmindful actions don't cause more suffering for other beings. But we're not so idealistic to think that we can totally get out of killing for the support of our body. This is actually bringing up some Right View, some Right Understanding, that in the support of this body, because of our wish to have this body and live, other beings are dying. Even if we become a vegetarian, a fruitarian or a vegan, stop wearing clothes or anything, we're not going to get out of it. There's no material way out of it. The only way out of it, according to what I understand, is to become enlightened, so that we don't seek the body any more and we break out of the cycle of birth and death.
As far as drowning rats, I would not drown the rats. That is deliberately, intentionally killing. We have to be very careful, as I was saying before about that. What we can do is that we have to be skilful in how we can try to avoid intentionally killing. I know at Wat Kow Tahm we're constantly trying to figure out ways how not to kill and to prevent killing. And it actually takes a lot more patience to actually look at that. Like you're going into the toilets and you see ants in the toilets, instead of being impatient with them and just using the toilet, we try to fish them out first. Patience. There are a lot of ants in the tropics!