The term 'Nasty Insects' can be summarized by two crossword solutions: wasps (5 letters) and LICE (4 letters). Wasps are flying insects that are typically black and yellow in color and have a narrow waist. They are known for their painful sting and are often found near flowers or garbage. LICE are small, wingless parasites that feed on the blood of humans and animals. They are usually found in the hair and can cause itching and irritation.