Which of the following regarding rodents is true?

The sighting of rats during the day is indeed an indication of severe infestation. Typically, rats are nocturnal creatures, meaning they are more active during the night. When they are seen during daylight hours, it can suggest that they are in search of food, water, or shelter due to a significant population pressure or an overcrowded environment. This behavior is a signal that the infestation has likely reached a point where the usual nocturnal habits are disrupted, leading to increased visibility during the daytime.

In contrast, the other options present misinformation. Rats are known to nest both indoors and outdoors, depending on their habitat. Not all rodent species are protected by law; in fact, many are considered pests and can be controlled. Lastly, rats and mice belong to different genera within the family Muridae, showcasing distinct characteristics and behaviors. Understanding these facts helps emphasize the importance of monitoring for signs of rodents, as early detection can mitigate health risks and property damage associated with infestations.