Awwww! They are just absolutely precious; thanks for rescuing them.
As for treats, mine really love steamed broccoli as well as other veggies. I give seeds and nuts sparingly as there are plenty in their mix and they're fattening. I would avoid anything sugary, too, like those yogurt drops they sell. Oats make a nice treat. I see other good suggestions here: http://www.thegerbils.com/maintenance3food.htm
As for other tips, the most important would be housing: never keep them in a cage. Ideally, they should be kept in at least a 20 gallon aquarium with deep bedding as they love to burrow. I use Kaytee Clean & Cozy(I get it off Petco.com or Chewy) and Eco Bedding(Amazon) mixed together as I'm going for as low dust/low allergen potential as possible(asthmatics) but you can also use Aspen bedding. For wheels, go for the wire-mesh looking types(preferably 9 inch ones) or the Med-large size silent spinner. They can get their tales caught in other wheels. They enjoy having hides/houses, TP rolls, wood chews, and access to a dust bath. You can use Chinchilla sand bath or just use sand(treated in the oven), which is what I use.
If you have any other questions, feel free to ask. I love the little guys.
Edit: I forgot to say: avoid plastic like the plague; they will chew it and it's not good for them.
My last gerbil (part of a trio) passed away several years ago. She lived to be just oer 4 years old
The American Gerbil Societ has a great web site with gerbil care info: http://www.agsgerbils.org/ I think they still have their Yahoo Group that you can join and ask other gerbils owners and breeders questions.
Gerbils like fruit and veggies. Fresh is best. A little piece is plenty. I used to give grapes, bananas, broccoli, carrots, corn, apples, pears, and other things. Don't give citrus fruits. Unsalted /unflower seeds and pumpkin seeds are also good treats. Pet stores sell various small animal treats.
I only use Carefresh bedding. AGS also recommends Carefresh or other similar paper bedding.
I kept my gerbils in a 15 gallon tank with a screen lid. It was roomy enough for 3 gerbils. The water bottle hung from a holder on the side of the tank, the mesh wheel hung from the screen lid (had to DIY that myself), there was a wooden house and a bowl. My gerbils had playtime outside of the tank. I turned an under-the-bed storage container into a gerbil playpen with a maze built out of tissue boxes connected with cardboard tubes and lots of bedding. I can PM you picturse of my set up if you want ideas.
The plastic cages with the tubes are all cute and whatnot but it's a huge PITA to clean all those tubes and pieces every week. Plus gerbils can chew their way out.
Gerbils being rodents with constantly growing teeth chew on everything so give them plenty of non-plastic things: wooden toys and sticks from the pet store, empty toilet paper and paper towel tubes (great way to recycle those), tissue boxes, etc. Plastic is easily shredded and the plastic shards can be ingested which can cause internal injury, much like how string can cause issues in a cat is ingested.
Look for an avian / exotic vet in your area just in case your gerbils need to be seen for a health issue. Overgrown teeth are common even if a gerbil has access to plenty of safe chew things.
My gerbils came with one of those plastic cages. I think I have a 20 gallon tank in storage, I'll have to look for it.
I use care fresh bedding and provide them with commercial wood sticks to chew. I also give them the tubes from paper towels and foil etc. they have a metal mesh wheel but they do not use it.
What kind of wood can a hideout be made of? I bought a plastic igloo but removed it when I saw they were chewing it up. I tried a ceramic hideout intended for chinchillas but they refused to use it.
Thanks for all the tips!
Some gerbils like the wheel, others not so much. I'd keep the wheel in the tank just in case your gerbils decide to give it a try.
Wood from fruit trees are safe to use as long as they have not been treated with any pesticides or stuff. Buy the wooden houses at the pet store if you're not sure if your local fruit trees have been treated or not. I used to buy this wooden house. It comes in different sizes, from mouse size to guinea pig size. The medium size is roomy enough for gerbils. A tissue box makes a great hideout but you'll need to replace it pretty frequently since it'll be turned into confetti very quickly.
PVC plumbing connection pieces make good tunels. The t-shaped piece, the elbow pieces, the Y shaped piece, etc. The PVC is really hard and while a gerbil will chew on it, the PVC doesn't shred easily. Any hardware store sells plumbing pieces for very cheap. The pieces come in various diameters so get the ones that a gerbil can easily fit through, maybe 3 or 4 inches diameter. I suggest soaking the pieces in a bleach bath for half an hour and then washing with hot soap and water before giving them to the gerbils.
A friend of mine had her gerbils in a tank wire top, filled with a play sand -peat moss mix 3/4 of the way up with some cardboard tudes added. The gerbils would make their own tunnels and nest and climbed to the top for their food and water and chewed the metal mess to keep their teeth down.