1. An accidental ingestion detecting apparatus comprising: a swallowing sensing unit which senses swallowing by an animal; a swallowing detecting unit which detects swallowing based on sensing data outputted by the swallowing sensing unit and which outputs swallowing information that is information related to the swallowing; a feeding information inputting unit which accepts input of information related to feeding of the animal and which outputs the information as feeding information; and an accidental ingestion determining unit which determines accidental ingestion by the animal, wherein the accidental ingestion determining unit determines accidental ingestion by the animal based on date/time information included in the swallowing information and date/time information included in the feeding information.