Authored by Leyla Billman of Pin-Up Pythons
Going Organic | Building your Rattery
Over the years I have been involved with snake ownership, I have sworn I would never get into rat breeding. Unfortunately, two stubborn live-feeders and my source of live rats suddenly no longer offering rats anymore dictated a change for the benefit of my snake population. What started as a simple pair of pet rats for my daughters has now evolved into a ten rat, 3:7, colony (and growing)! I have progressed from providing the occasional litter of feeders for my two stubborn snakes to constructing a CO2 chamber and providing food for all my collection, plus two friends’ snakes. It’s pretty safe to say that Pin-Up Pythons has earned the right to add “& Rattery” on the end of its name at this point!
Naturally, with all things animal-oriented, it is always a learning process, but this is a quick and dirty guide to starting your own small-scale rat breeding operation. Please bear in mind, the rats I breed are predominantly feeders for myself and a couple of friends’ use. Should you decide to expand your operation to vending at reptile shows or regularly selling pets, you will need to do further research on permits and such in your location.
Rat Breeding | The Basics
Rat breeding is very simple. These rodents are notorious for being extremely fertile and yielding a litter isn’t exactly rocket science, but it doesn’t hurt to know the basics. First, rats reach sexual maturity very early: females as early as 5 weeks and males between 6-7 weeks. This does not mean you will (or should) get a pregnant doe at 5 weeks, but the risk is there (so it is important to separate sexes by 4 weeks old).
Ideally, a doe should be bred when she is either 5 months old or 250 grams.
They go into heat every five days, so I typically will pair up rats for a 7-10 day stretch to make sure it takes. Bucks are usually good to breed once they hit 300 grams. Most does will not consider a very young buck as mate-worthy, so insure you have a senior male to breed if you are adding younger males to your colony.
The standard rule of thumb is you need at least one male for every six females.
I like to play with genetics a bit (might as well have fun while creating food, right?), so I have some variety in my boys. Do not introduce males to females who are still tending to a litter, because there is a chance the female will not be receptive and she WILL put him in his place if her children are present. I have quite a few females who have zero issues driving my huge buck into a corner when their babies are still dependent on them.
A common misconception is the males eating the young. Nothing is further from the truth!
Male mice do eat the young, but rats are fabulous fathers and love their kids! I let the females raise the babies to weaned status and then they go in with the bucks. The fathers are very attentive to the youngsters and do everything from bathing, playing, and teaching them how “to rat”.
Rat Gestation and Birth
Gestation in rats is 3 weeks (give or take a day or two). I try to pair up two females to be cage mates during gestation. Usually, females who give birth around the same time will help each other out in raising the babies. Even if one of the females isn’t pregnant, she will still play the role of babysitter so the mom can rest or eat. I do have one female who refuses to share a cage with another rat when she gives birth, she will fight aggressively with cage mates and steal babies from other moms. So, she gets her own birthing cage to avoid drama.
I strongly recommend charting weights throughout gestation, this way you can make sure everything is progressing as necessary. Every rat will be different, but usually once my rats hit the 400 gram range they are close. They will look like jelly donuts and will be sensitive to being picked up! They will start building a nest about 24 hours before giving birth. My most accurate indicator is fighting. Even my sweetest does will put the smack down on their buddies right before giving birth – if I hear a fight break out, I know babies will be arriving in a few hours.
The moms handle the process on their own for the most part. I let mine be until I’m sure mom has delivered her whole litter. After mom has rested a bit, I will go in with a treat and do a count. This also gives me a chance to remove any babies that didn’t make it. I do another count after 24 hours and remove any dead pups. After 24 hours it is rare to lose any pups. Sometimes mom will eat the deceased pups, but my does are inconsistent, so I go in and do the dirty work.
Rat Pup Rearing
Pups open their eyes at two weeks, they are mostly immobile up to that point, depending on mom for everything. But after the eyes open, they develop independence. I usually will sex mine right before the eyes pop open (you can Google resources for sexing, but at twelve days you can spot nipples on the females with ease…so if you are new to this, that is an easy tell). Since, most of mine are food, I really will only sex any that are catching my eye to see if they might fit into any breeding plans. Moms will wean pups between 3-4 weeks. Depending on what size you are raising for your snakes, plan two months for the entire breeding process from start to finish.
Establishing Your Colony
I am not going to spend a bunch of time discussing rat husbandry, because that is research imperative to working with rats. But I will say this: VENTILATION. Whatever setup you choose (be it a rack system or cages), make sure you have proper ventilation to avoid nasty things like respiratory infections AKA RIs. Also, fresh water (and lots of it, especially for nursing females) is important.
You need to decide how many rats you need and how much you need to produce for your snakes. I call this “rat math”. Rat math will give you a headache if you overthink it. But you do need to think through how often your snakes eat, what sizes they require, etc. It is possible that while you are establishing your colony, you may need to supplement with feeders from an outside source.
You will inevitably pick up new rats from litters. If you see a nice-looking female or a new color creep in, the temptation will be to add that rat to the colony to see how it progresses. Inbreeding is perfectly fine in rats. My whole colony stems from two rats I purchased back in September 2016. One black and white female and one blue and white male. I now have three males: the blue/white, a solid black, and a recently born champagne with pink eyes! My females are three black/white (various markings), a predominantly white with a black stripe, a solid blue with a white star, an almost solid black, and a blue/white. Lots of variety and it is interesting to see the occasional recessive gene jackpot like my champagne with pink eyes.
Female rats can be bred until they are 15-17 months old without issue. You have three options when you retire a breeder: you can cull and feed off, you can retire her as a pet, or you can retire her as a babysitter so she can continue to lend her motherly expertise to your new moms.
Most importantly though is temperament. Regardless if you have intent to handle them regularly, treat them as pets, or raise pets for sale, you will WANT nice rats. You must clean cages, you must feed…most importantly, you must retrieve pups now and then to feed off or cull. You do not want an aggressive mom drawing blood on your hand. That trait is passed down, so if it pops up – cull. I am not talking about a new mom who is a little jumpy or eager youngsters who nibble your fingers at feeding time. I am talking about rats who squeak every time you touch them or bite you intentionally. My kids can reach into any cage at any time and pick up any rat without issue. THAT is an ideal colony in my world. I can confidently sell off youngsters as pets or food without concern. Also, my rats who are fed off alive to my stubborn snakes will not attack my snakes.
How to Feed and Clean a Colony Without Going Broke
So, rat breeding is one of those things where if you do it wrong, you will end up paying more than if you just bought from somewhere else. I started with my original pair on Oxbow rat food and straight paper bedding. Soon, that small bag of food was gone in three days…and that was even mixed in with odds and ends from my pantry. Most breeders use Mazuri rat food and if you can find it at your local feed store, go for it! But I wasn’t as lucky, so I found Mazuri mini-pig feed. WHAT???? Yep, if you look at the feed nutritionally they are very similar. Both animals are omnivores, fed to produce feeders, and produce high-yield litters. One 25 pound bag costs $18 at my TSC and lasts my crew one month. Whereas I was paying similar for a tiny bag of Oxbow that lasted a few days. Also, some breeders will use dry dog food (I’ve done this in a pinch).
Rats are omnivores so I have given them stuff from my pantry (like oats, dried pasta, and nuts), leftovers from cooking dinner (various veggies – no avocados – chicken gizzards/hearts/livers, cheese), they love dog biscuits as a treat (great for gnawing activity, but makes my dog mad HA!). I ALWAYS give my does, who have just given birth, eggs. The extra protein right after giving birth is awesome. My mom who gave me a litter on Easter enjoyed some hard-boiled eggs and leftover lamb from dinner! If you are unsure, please Google foods rats can and cannot eat.
For bedding, I use a base of equine pellets (these are kiln dried pine pellets – totally safe for snakes) and top with a couple of handfuls of paper bedding. The paper bedding is pricey, but my rats seem to like it for their litters. The equine pellets run about $5 for a 40 pound bag. I work with horses as well and a little goes a long way with the horses! It does a great job with odor control and a couple of handfuls will absorb rat urine just fine. You will want to plan to clean your cages twice a week to keep the smell down. I use Simple Green across the board with my snakes and rats, but there are other cleaners you can buy that are bio-friendly.
Pets, Feeders, Pricing, and The Grim Business of Culling
So, all of my breeders, minus one or two rats, are pets. They are handled frequently and have names, all of the offspring are handled from day one. The primary reason I titled this article “Going Organic” is because not only do I control what my rats eat and their living conditions, BUT I know that they have received the best life possible. I even choose to use wire cages and keep our rats in common areas, so they can regularly interact with people. While the clear majority of our offspring have been feeders, a few did end up as pets for kids. And they ended up being excellent pets, I credit our regular socialization and interaction from the moment the litter drops.
As stated previously, I do provide feeders to a couple of friends with snakes. I charge bulk feeder pricing (comparable to Perfect Prey or Big Cheese), mainly because they are friends and I am not looking to profit. For pets, I charge $10 per rat. The reason for the increase is to put value on the level of responsibility of taking in a pet. If I charged $1.75 for a small rat, it might seem disposable. Also, pet rats at big box pet stores tend to be priced similarly. I do try to vet potential adopters (and only sell via word of mouth) and spend a lot of time educating adopters on the rats. I only sell same-sex pairs/groups, I do not sell singles (unless there is already another rat at the new home). Rats are too social and I don’t want to set up my babies for failure.
Culling. If you breed rats at some point you will need to learn how to cull, whether it be for humane reasons (maybe a rat is suffering due to a medical problem) or you need frozen/thawed for feeders. You CAN do cervical dislocation, if you are confident with it. I don’t, because I feel that is a method if you don’t confidently know what you are doing, you can risk causing suffering to the animal.
I prefer CO2. It is quick, cheap, and effective. I built my chamber for around $10, not including the dry ice. Simply take a Sterilite 15QT tub and find a plastic container with a lid that will fit inside it (you will want it to be about half the size of the main tub). Solder holes in the sides of the smaller container. This container will have your dry ice in it, you need it to have a lid and the holes to be higher up on the sides, so the rats don’t come in direct contact with the ice. I put some bedding in the base of the main tub, as the rats will defecate sometimes. You can purchase dry ice at larger grocery stores like Kroger, Meijer, or Wal-Mart. Handle your dry ice carefully! I break mine on the pavement outside, while still in the plastic bag and pour the pieces into the smaller container. Put your rats in the main tub, add 1 cup of water to your dry ice container, it will start to smoke. Quickly put the lid back on and put that container in the main tub with the rats and lock the lid. Depending on the age of the rats, it should only take a minute.
Make sure your rats are no longer breathing. Remove and put in a Ziploc freezer bag labeled with the age of the rats and the date of culling. This is important, rats need to stay in the freezer for 30 days before use. This is to allow the gasses to dissipate, but also to kill any parasites. I usually will weigh the rats after they are frozen and write the ranges on the bag at that point.
Quick note about culling pups. Baby rats’ lungs are not fully developed until after 10 days, so you CANNOT CO2 them that young, they need to be frozen alive. I don’t cull anything under 12 days as I don’t have a need nor am I comfortable freezing them alive. I will note that it takes pups (12 days) a bit more time to die in the chamber than weaned or older rats. If you need pups, cull at 12-14 days. For weaned rats, cull at 3 weeks. For small rats, 4 weeks should be ideal.
So that’s it! It seems a bit overwhelming, I know. But after a litter or two, it becomes much easier. I will say the first time you feed off a rat you have produced yourself, it is bittersweet. There is a sense of pride in producing the best food possible for your snakes, ethically. And honestly, I have noticed better feeding responses from my snakes since raising their food myself.