Instead of lungs, insects breathe with a network of tiny tubes called tracheae. Air enters the tubes through a row of holes along an insect’s abdomen. The air then diffuses down the blind-ended tracheae. Since the biggest bugs have the longest tracheae, they should need the most oxygen to be able to breathe.
There are no pain receptors in the brain itself. But he meninges (coverings around the brain), periosteum (coverings on the bones), and the scalp all have pain receptors. Surgery can be done on the brain and technically the brain does not feel that pain. With that said, the brain is the tool we use to detect pain.
Brownie points in modern usage are a hypothetical social currency, which can be acquired by doing good deeds or earning favor in the eyes of another, often one’s superior. In New Zealand slang, the expression also carries the derisory connotation of having accomplished something petty or otherwise unimportant.