Yes. I do not claim to be ethically pure. I am fully aware that rats, snakes and many other animals are killed while crops are harvested or planted for my vegan diet. I also know that I contribute to environmental damage whenever I drive my car. I do not choose vegetarian food to achieve personal purity, which is impossible. I do it to reduce animal suffering.
When our society takes animal rights seriously, we will need to reform how we harvest crops and build roads so that we try to reduce the number of animals killed. This will not happen as long as society continues to see animals only as a food source. I realise that in one way I contribute to animal deaths simply by participating in society. Still, I believe withdrawing from society would cause more harm, because I would lose the chance to influence others and encourage them to become vegetarian.
Although animals are killed while crops are grown for vegetarian and vegan diets, it should be emphasised that many more animals are killed while crops are grown for a meat-based diet. This is because farmed animals need to be fed crops, and only a small part of the food they eat is converted into meat for people. Far fewer animals would die during crop production if people ate these plants directly instead of feeding them to farmed animals.
Finally, no matter how hard we try to avoid it, animals will always be killed accidentally in events connected with human life. It is the same as the fact that people will always die in road accidents. But the possibility that we might hit someone with a car does not mean it is all right to do so intentionally.