How many teeth does a rat have? - briefly
Rats have a total of 16 teeth, with two incisors in each jaw and six molars on each side. This dentition is adapted for gnawing and chewing solid foods.
How many teeth does a rat have? - in detail
Rats possess a total of sixteen teeth. Their dental formula is expressed as 1/1 incisors, 0/0 canines, 0/0 premolars, and 3/3 molars, meaning each jaw contains one incisor and three molars on both the upper and lower sides. Consequently, the animal has two incisors in the upper jaw and two in the lower, accompanied by six molars per jaw.
All four incisors are open‑rooted and grow continuously throughout life. The enamel is restricted to the front surface, creating a self‑sharpening edge as the softer dentin behind wears away. This adaptation enables persistent gnawing of hard materials such as wood, plastic, and seeds.
Molars are also hypsodont (high‑crowned) but do not exhibit the same degree of growth as incisors. They erupt fully after the juvenile stage and remain functional for the animal’s lifespan, providing grinding surfaces for plant matter and occasional animal protein.
Dental health depends on a diet that promotes natural wear. Soft, processed foods can lead to overgrowth of incisors, resulting in malocclusion, difficulty eating, and secondary infections. Regular access to fibrous or hard items—like chew sticks, nuts, or untreated wood—helps maintain proper tooth length and alignment.
In summary, a rat’s mouth contains sixteen teeth: four continuously growing incisors and twelve molars, with no canines or premolars. The specialized structure of these teeth supports the species’ gnawing behavior and overall survival.