Rat care
Rats are very easy to care for as pets. Their average lifespan is 2.5-3 years. As colony animals, they need constant stimulus and socialization. It is always best to keep them in pairs or more, as individuals that are housed alone can become bored and sometimes even aggressive.
Caging requirements:
Rats are inquisitive and intelligent, they are quite capable of escaping from enclosures you would expect to be escape-proof. When using an aquarium, make sure the lid is either locking or has enough weight that a full grown rat can't lift it. When using metal bar cages, make sure the bars are close enough together so the rat cannot fit it's head through, if it can, it can get all the way out!!! Even many cages marketed for rats will not contain a baby rat (my learning curve included a weanling getting out of 1/4” squared wire mesh!!)
There are many viable bedding options to choose from, such as carefresh, wood chips or shavings (not cedar), shredded paper, pine pellets, and many others readily available from your nearest pet or livestock supply store.
Food and Water:
One of the easiest diets to feed rats is the “block” type diets. This type of food does not allow for choosy eating, everything they need is included in the blocks, as long as you go with a high quality food. Of course there are many mixed diets to choose from as well, however: in my experience, most rats will choose the foods out of the mix that they want, and leave the rest. Therefore much goes to waste in the end and I have found it more economical to feed blocks supplemented with their favorite treats. Fruits and vegetables are instrumental in their diets. Hard, low water content veggies and fruit such as kale, leaf lettuce, cauliflower, broccoli, apples, pears, carrots and squash are very nutritious and won't cause diarrhoea the way that high water content items such as grapes, cucumbers, head lettuce, and celery will. Do to their very small size, diarrhoea is capable of killing a rat in 1 day, so keeping with the correct fresh foods is imperative. As with any other creatures we take responsibility for, they need a constant supply of clean, fresh water at all times. Again, because of their small size, dehydration can happen very quickly and is deadly.
Socialization
rats are very social creatures who were not meant to live alone. It is always recommended to keep them in pairs or more, both males and females will colonize naturally if put together at a young age. When trying to introduce 2 adults together who have previously lived alone takes more care, they should be introduced to each other through a barrier, even the most untrained eye can catch aggression displays from rats, they are VERY OBVIOUS about it!! So long as they show no overt aggression within 2 days, they should be fine to be put in the same cage. Make sure that when you do this you have enough time to watch their initial interactions to be assured they are OK with each other. Most rats will welcome company of their own kind quickly and easily.
Breeding
before purchasing your breeding stock, there are things that need to be done. First, you need to decide the size of your breeding colony. Many people like a ratio of about 1.4 (1 male 4 females), personally I have a larger ratio (1.10) which allows me to have only 1 colony cage and the one male seems to get the job done, no problems!! Second, now you have to purchase/build your caging system. One large cage (I use a Guinea pig cage) for the colony to live in, and 1 cage/bin for each breeding female. Now it is time to find your breeding stock. If you start with healthy, high quality rats, then that is what you will produce (so long as you KEEP them healthy of course!!) Pay the bigger buck for better breeder stock and you will have more success and far less headaches in the end. Both your male and your female should be 12 weeks before any attempt at breeding is done. I personally do not put a female into the colony tank until 16 weeks. Smaller females don't have more problems with pregnancy or birth and their pups are usually the same size as any other females would be, but their litters will be far smaller in numbers, and of course, breeding them early does not allow for the proper growth to continue as they are using their calories for their babies instead of themselves.
A female is capable of becoming pregnant as early as 5-6 weeks old and continues her fertility cycle until approximately 1.5 years old. She will go into heat every 5 days, interrupted only by the 21 day pregnancy. The day she gives birth she is in heat again, immediately. At about 12-15 months, her litters will start declining regularly in numbers until, between 18-21 months, she will stop getting pregnant all together. A male can continue to impregnate a female right up until death, however his fertility rates and will go down and pup mortality will go up as his virility fades. I personally replace my females at 18 mos and my males at 2 yrs old.
So you have your caging ready, you have purchased your breeding colony and now your watching for signs of pregnancy. The female will start to thicken just in front of her back legs and her nipples will start to become visible. Once she is showing a “pear-shaped” appearance is when you transfer her into a brood box/cage. Once she is alone you can start to supplement her diet with vegetables high in iron such as kale, parsley, broccoli and green beans. She is also going to need some extra protein and fat. You can supplement their diet with a high quality puppy or kitten food, or you can supplement the protein/fat needs with things such as plain nuts, beans, peas, and avocado’s.
A female is pregnant for 21 days, they usually give birth in the late hours of the night, or early hours of the morning. For most litters, you will wake up to 10-20 pink jelly beans in the brood box!! Baby rats are born without hair, without tails, and with ears and eyes shut tight.
Birth to weaning
birth – day 7 (week 1) – Pinky stage – within this week, you will start to see pigment (if any present) coming into the skin. Even dark skinned rats are born pink, they get their colour in the first 3-4 days. Most mothers will not have a problem with minor handling of new born pups. But keep it to a minimum, ie: to clean out the birth mess from the nest.
Days 8-14 (weeks 2) – Fuzzy stage- During this week of development you may start to see the eyes open just a crack, the swelling in the ears will go down and the babies will now be able to hear. A peach fuzz will start to grow in, and the babies will start to do a little moving around the enclosure (although mamma will run around trying to put them back!!) again some handling is OK, but mamma won't want you to hold anyone for too long.
Days 15-21 (week 3) – Hopper stage- Now they are active!! eyes are completely open, they are fully mobile and mamma is now teaching them the merits of solid food and drinking water from a bottle!! Be careful opening the cage at this point, those babies move faster than you do!! Anytime from this point forward, you may handle the babies as much as you wish.
Days 22-28 (week 4)- weanling stage- This is the last week they will have any need of mamma, finishing off the lessons on solid foods and teaching very important social skills will be her last responsibility to these babies. They now look like miniature versions of their adult selves and are ready to let mamma go back up into the colony cage!!
Days 29- and up- Juvenile stage- You will need to separate male from female by this time, as you don't want babies birthing babies. It is very easy to tell gender at this stage as the males testicles have already descended.
Controlling/Staggering your colony cage
In order not to have 10 litters born at once, and to prevent the male from being left alone in the big colony cage, you can stagger when you put your females into the colony cage. When I started, I put one female in per week until the colony was complete and to continue with the staggering, a female may get a 1-6 day break in her brood cage after her litter is gone and before going back up to the colony cage. This way (as I breed for both pet quality and food quality) I have many litters at different stages of development at the same time, as well as my male never having to be left alone in the colony cage until one of his girls are ready to come back to him!!
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