If you're vegan or vegetarian, chances are you've been deemed 'hypocritical' at some point in your life. It's usually non-vegans who are the hypocritical ones - so why would we ever be labelled as such? Well, perhaps we've swatted a blood-sucking mosquito. Perhaps we've bug-sprayed a large spider infestation (yeah, they're technically not insects, but we'll consider them for argument's sake). Perhaps we've stepped on an ant while trotting down the side-walk.
All of these scenarios are probable. It's likely they've happened to you. I know for sure that I've dealt with all of these scenarios, and I've been vegan all the while. Some non-vegans (some vegans as well, probably) may look upon these acts as cruel and therefore not vegan. I, however, disagree.
"As vegans, perhaps we've swatted a blood-sucking mosquito. Perhaps we've bug-sprayed a large spider infestation. Perhaps we've stepped on an ant while trotting down the side-walk."
In most cases, it's best to shoo the bothersome insect away before resorting to killing it. That's usually my choice of action. If you live in an area where mosquitoes are renowned for carrying infectious diseases, however, it's better to rid of them as swiftly as possible. To reiterate - this is an act of self-defence rather than callous greed, so it is not cruel. It is not anti-vegan.
Taking care of a spider infestation is a similar act of self-defence. If these potentially venomous creatures have invaded your home, ridding of the danger as soon as possible is the safest option. In the case of a very large infestation, poison is the simplest, safest and quickest way to remove the danger. Protecting yourself and your family is, again, not anti-vegan.
"Always and only choose the 'kill-method' as a last resort. If any other viable option exists, choose it."
If any larger animal posed an immediate threat to us, our homes, or our families, we would take care of the imminent danger as soon as possible through any means necessary. I believe we should use the same approach when dealing with the smallest of critters. After all, we can make a much larger impact on the world while we're alive than while we're ill or deceased!
Regarding stepping on ants: this is something I'd call an accident. An often regrettable and dispiriting accident, but an accident nonetheless. I would never, ever go out of my way to kill an ant. I'm saddened when I watch people purposely step on them, especially children. I see it as a sign of a complete lack of respect for life.
Compassionate people go out of their way to avoid injuring all creatures, ants included. Sometimes, however, we make mistakes. Sometimes we don't see the tiny critters. Sometimes we misstep. Completely unintentional harm is not comparable to the intentional harm of paying for animals to be killed and eating their dead bodies - as such, it is not 'unvegan'.
What about termites? Again, this is a case of home-invasion. If a rogue creature has entered your habitat with the intent of destroying it, you must do whatever's plausible to rid of the problem - as any animal would do. Sometimes, sadly, the only plausible option is to kill.
"Completely unintentional harm is not comparable to the intentional harm of paying for animals to be killed and eating their dead bodies - as such, it is not 'unvegan'."
All of this is only my opinion, and vegans have differing views on the matter. I don't speak for all vegans and vegetarians. Some don't agree with killing in any way, shape or form; and believe it is better to sacrifice our own lives than those of other sentient beings. I respect this opinion, but to me, it's unrealistic. No matter how heart-wrenching taking another life may be, it's unfair to beat yourself up. Our lives are important too, and - as aforementioned - we can't make a real impact while we're dead. Respect your own life and do whatever you can to preserve it, so long as you're trying your very best to avoid harming others. That's called being vegan.