Insect bites. Most insect bites produce only minor irritation, with symptoms such as: swelling at the site of the bite. Itching or burning. Local numbness or tingling. Bites of poisonous spiders and scorpions may produce these symptoms: intense pain at the site of the wound. Stiffness or joint pain.Muscle spasms. Abdominal pain, nausea, or vomiting. Fever or chills.Difficulty breathing or swallowing.