A sensitive period of brain development is a period during which the brain is especially impacted by certain factors or experiences. As brain growth is the fastest before child's birth and during early childhood, it's the most sensitive during this time. That's why this is the key period for later health and development. In addition to genes, brain development may depend on the presence of all listed factors. Malnutrition and exposure to infections and toxins may negatively affect the way a child's brain is developing.
Yes, I agree that bedbugs are parasites because in the text it states that “bedbugs became even harder to kill” and I can tell that they are parasites because they are hard to kill and they are also doing harm to people when they try sleep or also lay on their beds.
