Just having them as pets - walking them leads to a lot of socializing, or pitting them against each other, or using them as geriatric guard toddlers - they sent everyone off their lawn.
@kuru That's what you get from applying Occam's Razor. Or maybe it is that Occam's Razor is meant to not advise the answer, that needs the least amount of assumptions, but the one that induces the least amount of effort?