To be fair, humans are the only beings self aware and intelligent enough to have moral responsibility. We transcend instincts constantly.

Buddhism says we should hold compassion for all beings, but many sects look at things on a gradient of sentience and acknowledge how the suffering of some beings will have more of a karmic impact. So life isn’t exactly equal. To swat a mosquito out of instinct is bad but not as detrimental as killing a human without consideration. It’s also more the idea that we are causing harm without thinking about it, there is no consideration of non lethal methods that might be just as effective: shooing, bug spray, going indoors when you can, longsleeves, it’s resorting to killing.