Fancy rats are domesticated Norway Rats who in the wild, use aggression to defend territory and protect babies. As a prey species, they are naturally fearful of new situations. As they have been domesticated for over 100 years, responsible sources of rats have been actively breeding out these traits to produce pet quality rats. Unfortunately, pet stores, feeder breeders, and backyard breeders are not progressing the species to be aggression-free and confident. Even ethical responsible breeders can have it randomly pop up, but the chances for aggression from these breeders is significantly smaller if properly bred. Aggression and fearfullness is genetic and it’s important to get rats from good sources to ensure the risk is low.
Considerations
Rats’ teeth are as hard as iron and sharp, so rat bites to humans can be a serious issue. Hospitalization and nerve damage are common from rat bites, and Rat Bite Fever can result which can be fatal to children or immunocompromised people. Now this is incredibly rare, but it’s important to know the consequences and ethically source our rats. Rat bites inflicted upon other rats can easily land a vet trip as rats can fight to the death.
Rats are arguably the best small animal to keep as pets due to their ability to bond to their owners and intelligence, so it’s important to be educated on aggressive rats. Most of the time, you can “fix” aggression in rats.
Types of Aggression
Aggression in rats has 2 broad types with a few sub-types. The main ones are human-oriented and rat-oriented. Rat-oriented is typically hormonal. For males it is due to excess testosterone. Aggression due to pregnancy or the presence of babies for females is called maternal aggression. Females can also develop hormonal aggression without the presence of babies. Hormonal and maternal aggression come from excess hormones which makes rats see other rats and sometimes humans as a threat to eliminate. The solution for hormonal and maternal aggression is sterilization which almost always reduces the hormones to a level that calms their aggression down. Babies from a maternally or hormonally aggressive rat should not be adopted out, they are of a higher risk of becoming aggressive due to genetics. Babies should be humanely euthanized promptly after birth or kept to live out their days in the home they are born into as this will prevent aggressive rats from further plaguing the pet community and rescues. Euthanizing the babies promptly after birth will often help the mom rat return to herself from before the pregnancy. Hormonally aggressive rats can also skip a generation, making it a problem in many lines of novice breeders or pet stores.
When a rat lashes out at a human, it’s not acting out of malice, it is trying to communicate. We should figure out what the rat trying to tell us, and why? Human-oriented aggressive rats who are not aggressive to rats often have something deeper going on we need to address, but usually it’s at the fault of the human.
Common causes of human-oriented aggression is mishandling, unsuitable housing conditions, illness, or hormonal changes. Fearful rats or rats that are ill are very likely to bite. Red eyed-rats are almost completely blind and require special care as they are less likely to be able to tell apart food from hands and are easily spooked by quick sudden movements or handling. Often, these behaviors improve drastically with proper care, handling, and, when needed, sterilization. Rats aren’t inherently bad, they are just reacting to distressing situations.
If you’ve had your rat for less than a month, they are still getting acquainted with their new surroundings and you may be moving too fast with interactions. Go at the pace they are comfortable with, checkout my blog on how to bond with new rats.
To handle rats, gently scoop them up from below, do not approach them with a claw-like appendage from above that resembles a hawk. Use 2 hands when moving them and support them against your chest when handling them to make them feel safer. Immediately offer treats after any interaction to associate handling with a positive experience. Always talk to them before going to touch them to “announce” your prescense as rats have terrible eyesight and may not even know you are picking them up until you touch them. This would spook anyone to be grabbed unknowingly and yanked into the air. Children should be taught to move slowly and speak quietly and how to properly handle rats and give them time to settle into a new environment before starting interactions.
If you’ve had them for longer than that, and the aggression is developing or progressing around the 4-12 month old age, it is either hormonal or a sign of illness. An exotic vet can help you determine the cause and facilitate sterilization if they are a candidate.
Housing Conditions Impact
Solo rats are more likely to develop aggression as they need same-species companionship. They need at least 2 square feet per rat with a lot of enrichment via foraging, climbing opportunities, sleeping spaces, items to chew, and opportunities to dig. Since they are as a intelligent as a human child and have the mental stimulation needs of a puppy, they will develop neurological issues if their needs are not met. They have incredible sense of smell so they may also be reacting to other pets in your home, the smell of food on your hands, or any strong scents like hand soap. Wash your hands before you interact with unscented soap and don’t approach your rats with hands smelling like a dog, unfamiliar rats, or food. Loud noises near the cage like a dryer or young children may be stressful for them causing them to bite out of fear.
Another environmental consideration is if you only have 2 rats. Rats do best in groups of 3 or more as a clearly established alpha will rise and their instinct to have a heirarchy will happen. Only having 2, sometimes an alpha can still rise and this will cause the lower rat to be constantly picked on. Introducing 2 more babies (because you shouldn’t ever get a solo rat even if you already have rats) will help level out the hierarchy and take some of the tension of your original 2nd rat. Make sure to do a proper quarantine and introductions (check out my blog on introductions) to minimize dominance aggression.
Food Aggression Subtype
Food aggression is a subtype that doesn’t fit into human or rat-oriented aggression and typically isn’t related to hormones or genetics. I’ve found that food aggressive rats will be handsy and sometimes nippy to both humans and rats. These rats have an extremely high food drive and were not taught by their mom rat and siblings when young to “be gentle or you’ll get put in your place”. You can train them to be gentle by offering a metal spoon with wet treats as the only treat for a few weeks until you notice they don’t bite and instead lick anytime food is presented. The metal spoon will be unpleasant if they bite and the wet food teaches them that we don’t grab, bite and run when given food. NEVER feed treats through the bars this is how they mistake fingers for food. Occasionally is okay if they have proven they won’t chomp fingers but don’t teach rats this habit especially if you have guests who will visit the rats or children.
Conclusion
Every rat deserves a chance to be understood so we shouldn’t immediately give up on them, we should exhaust all options to figure out what they are communicating. Getting our rats from responsible sources like ethical breeders vastly decreases the risk of aggression in rats, check out my blog on “where to get pet rats” for more information as not every breeder is good or ethical as they claim. Remember that aggression can almost always be fixed! Don’t give up the the rats, there are many resources to help you and them.
Ultimately if you’ve exhausted all these options (gentle training, sterilization, new rat group dynamics, proper introduction and re-introductions, vet checks) and your rat is still aggressive or incredibly fearful and lashing out by biting you, quality of life should be considered for humane euthanasia. Imagine living your daily life so terrified of your caretaker or being sterilized but still seeing every moving thing as a threat, you are not happy or living a good life. Speak to your exotic vet about this option as a last resort or if you are not comfortable with the situation. Please don’t rehome aggressive rats to be somebody else’s problem. Moving rats is very stressful to them and can cause further damage.
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