Whaaaa??? What happened to Tori?! :'(
I'm so sorry to hear this! I hope your coping okay! *hugs*
Rats vs Hamsters...
RATS. (I have 8 so I might be a little biased though!)
Which cage do you have? Because I know of a few cages that say they are suitable for rats, but they arn't tall enough. Rats LOVE climbing and need a LOT of room for enrichment.
As for the substrate i'd avoid anything woodbased. My girls are all litter trained, they don't have a substrate and just have litter trays, but I did use fleece for a long time. I have also used recycled paper pellets and chopped up cardboard, much like megazorb.
Many people use a paper based cat litter as its not dusty and has no real scent to it so it doesn't affect their breathing.
Carewise, rats and hamsters are very different.
Rats require a varied diet thats high in protein (around 16%) and they will need additional foods as well such as boiled egg and cooked meats such as chicken to provide them with extra protein (and its a lovely treat for them!)
My rats get a lot of my leftovers as well. They've had chicken pie, christmas dinner, spag bol and various pasta salads. They are designed to eat pretty much anything, though they should be fed rat pellets the majority of the time!
My rats love mealworms, baby food and dried fruit and nuts too
Attention wise, rats need a whole lot more attention than hamsters as you know and must must must be kept in atleast a pair! They need company and without it they can suffer from depression and develop health and behavioural problems.
Rats need a large cage with more height than floor space idealy. Then ropes and enrichment can be hung across the cage giving them things to climb on, mimicking their natural behaviours.
Royal Suite 95 Double Ferret Cage |Great deals at zooplus
This is the cage I have for my 8 girls. Its suitable for up to 12 rats, but 8 is the max i'd have in there at once.
A suitable starter cage is this one:
Furet Plus Rat Cage | Pets At Home
and this is the one I started off with. Its suitable for 2-3 rats, but if you were wanting males, i'd go with something a little larger just because males can get a lot larger than females and so that there is room for them to get away from eachother if there is a scuffle!
I had it with two females in, and did have it with another 3 girls in as well (at another point) and I'd say its better to have 2 ratties in that cage, rather than 3.
Enrichment!
They need a lot of it, go for ropes and cargo nets. Little wooden ledges, hammocks and sputniks are great as well!
Rats make amazing pets, you can train them to do tricks, they can learn their names, they really do want to spend time with you and are honestly very much like dogs! They are incredibly expensive and are prone to respiratory problems and tumours (and they are a little stinky!) but they are worth it!