Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to clean your rat's teeth [title] Learn about your rat's dental needs. [step] Rats do not usually need any dental care, including brushing. Rat molars are located inside of a pouch in the back of their mouths behind a section of gums called the diastema.

Ending1: A veterinarian has to use a speculum to dilate the pouch that contains the molars, so they are not accessible for brushing. The only visible teeth in your rat's mouth are the yellow or orange colored incisors in the front of his mouth. Ending2: This pouch of diastema grows into a pipe, with a series of holes along the bottom. [substeps] This gum can get trapped under the teeth, reducing their ability to breathe. Ending3: These will appear to have a tooth that grows out of the pouch. If your rat has a less common dental disease, such as perianal artery disease, your rat will probably not need dental care. Ending4: These are small teeth that you clean regularly using your hands. [substeps] Although these teeth do not need to be cleaned regularly, rat molars can be painful and produce bacteria.

Answer format: ending1/ending2/ending3/ending4