Rats are naturally very clean animals and spend a significant portion of their day (up to two hours) grooming.
Use shallow, lukewarm water and unscented, pet-safe soap.
The rodent wasn't "showering" for fun; it was likely trying to remove the soap from its fur, which can be irritating or stressful for rodents. 🐁 Natural Rat Grooming Habits
Rats often engage in "allogrooming," where they clean each other to strengthen social bonds and reach difficult spots. 🚿 Guidelines for Pet Owners
Do you have any other details, like the or the website where you saw it?
Only if they are exceptionally dirty, have skin conditions, or to help with introductions of new cage mates.
Be aware that immersion in water can be highly stressful for them.
