Rats do not necessarily have bad teeth. However, as their prominent incisors constantly grow throughout their lifetime, the rodents often need to gnaw them down to prevent overgrowth – a process that can leave them looking uneven or discoloured. Importantly, though, despite their poor appearance, rats’ teeth are highly specialised to maximise the environments they live in. The long, sharp incisors grant masterful levels of tearing and gnawing, while smaller molars enable torn food to be crushed prior to swallowing. Lastly, due to the harsh evolutionary pressures faced by the species, it can be argued that diverting energy resources to the perfection of teeth could limit their ability to survive day to day.