Too late?

Question
So I've had my rat since he was a baby, and he's almost 5 months old now. I'm trying to convince my grandparents to let me get him a friend, because he always seems so lonely and sad, especially since my schedule doesn't give me much time to spend with him. I really try, but I still feel like I'm not doing enough.

He's been alone all this time, so would it be too late to try to introduce him to a cagemate?

Answer
You absolutely need to get him a cagemate.  It is not fair to have him spend the rest of his life alone.  Even if you COULD spend more time with him, you could never replace one of his own kind.  Cagemates will sleep and snuggle together, groom each other, play together, wrestle, etc....something you could never give him.  Besides, nighttime (when you are asleep) is a rat's most active time, and he is spending that time alone...it's solitary confinement.

Here is a quote from my breeder's web site (and this basically summarizes what is known from research on rats):

"...it is essential that you have at least two rats of same gender.  Lone rats (no matter how much attention you give them) very frequently end up being antisocial, timid, depressed, or even aggressive. Rats separated from a social group too early or late in life have been found to exhibit symptoms similar to that of  schizophrenia. Nothing wrong with having a pet for your pet!  If you're afraid that one wont be as friendly because he has a buddy, there is no need. Rats are social animals, and will only be more friendly with you if they have a buddy.  A buddy companion adds a whole different element to your rats. They will be more confident, fun to interact with and watch, as well as have better mental and physical health (which results in lower vet costs in the long run). Really, one extra rat hardly makes any difference as far as care and feeding is concerned, but it makes a world of difference to the rats!"

Please show this to your grandparents and hopefully they will understand the importance.  Also let them know that it hardly takes more time or cost to have 2 rats as one.  Once you convince them, you need to know that male rats are very territorial and often it is difficult and time-consuming with introductions.  Fighting for establishing dominance of one over the other is expected.  In many cases, with time and patience, 2 males can successfully be introduced.  Sometimes, however, they may be too violent with each other (or one to the other).  In this case, the more dominant rat (or sometimes both) will need to be neutered to reduce the male hormones that cause aggression.

But do take one step at a time...the first being convincing your grandparents.  Good luck and when they agree (hope), you can write back to me about anything else you need to know, including quarantining the new rat, introductions, etc.