How do you know if you have a yestinfation?

Yestinfation is not a recognized medical or psychological condition, so if you're referring to a specific term, it may be a misunderstanding or typo. If you meant "infestation," signs typically include noticing an unusual number of pests or their droppings, damage to property, or irritating symptoms like bites or itching. If you're experiencing issues or symptoms that concern you, it's best to consult a professional for accurate identification and advice.