What ' s your gamertag <| sep |> Seen a lot of rats deal with death . I don ' t think they really understand it , never seen a rat interested in the dead body of a cage mate or family member but I do think they miss a rat when they go . I ' ve seen rats become lethargic , eat less , explore less . I have seen behaviour I would describe as mourning , but I ' ve also seen rats totally oblivious to the loss of a friend . As long as you have two you should be fine . They may be a bit more needy , a bit less playful , they may act out of sorts or be a little money but in the end they will be fine . Rats are very enduring beasts as long as they have another rat to fight over the water bottle with . Good luck to you and your boys