expression
not care at all; not be bothered in the slightest
Idiomatic expression meaning to be completely untroubled or unaffected by something, as if it were as trivial as a mosquito bite. Often used in negative constructions.
彼は批判されても蚊の食うほどにも思わぬ様子だった。
He seemed completely unfazed by the criticism.
あの人は失敗を蚊の食うほどにも思わぬらしい。
That person doesn't seem to care about failure at all.
Literally 'not even think of it as much as a mosquito bite'. The phrase uses the image of a mosquito bite as something trivial to express complete indifference.