Rats are extremely intelligent, in case you haven't had the pleasure of experiencing their smarts for yourself.
Scientists have performed studies with sounds and food and discovered they understand much more than we used to think.
Rats understand causal relationships, something scientists thought only humans and some higher primates could understand. This puts rats way up there on the list of the smartest animals!
So make sure you provide enrichment and activities for your rat to keep them busy when you can't play with them. Try making a toy for them to chew, or a maze for them to navigate.
Has your rat done anything to show off their intelligence?