Yes*. What bugs don't explain would be the difference between "unlucky" and "lucky". We have horses on different rations in our barn, and as far as I can tell,

Yes*. What bugs don't explain would be the difference between "unlucky" and "lucky". We have horses on different rations in our barn, and as far as I can tell, they all attract about the same number of bugs, but the sparrows tend to hang out way more with the ones on richer rations than they do with the ones on leaner. * eg https://news.ycombinator.com/item?id=41215084 https://news.ycombinator.com/item?id=41215084 (and I'm also aware that sparrows in winter appreciate half a kilowatt of heat per large animal, which is also independent of ration)