> As well for humans, you will have to consider demographical data and other data like gender, height, weight, body fat, in general how healthy the human is etc. which lead to even more questions.
You could control that out to an extent by painting half of each volunteer, and then comparing the number of bites on each side.
Of course you'd want to randomise which side was painted, in case the insects prefer to bite one rather than the other.
It’s unlikely the effect would work at all like that. Insects are certainly able to estimate the full figure, and with the hard break in stripes down the center the results would probably be tainted
You could control that out to an extent by painting half of each volunteer, and then comparing the number of bites on each side.
Of course you'd want to randomise which side was painted, in case the insects prefer to bite one rather than the other.