The neutral space method (moderate use)
What is it: Rats are introduced in a neutral space, in some cases the rats are made neutral themselves by adding a drop of vanilla to them masking there natural smell and making them smell similar. In most cases low level scuffles are allowed but any large fights that may cause injury are interrupted or separated. After a length or time the rats are separated and return to their own cage. This is repeated a number of times until the rats seem disinterested in each other or become friends, they are then moved into a fully cleaned out cage and the above is repeated or if it goes well they move in permanently.
Why: a neutral space belongs to no one so they do not feel the need to defend as hard (reducing the intensity of the fighting), repeated introductions build familiarity without allowing it to escalate, all rats are in the same situation creating an equal platform to build the group from, all rats smell similar (meaning it is less easy to distinguish newcomers)
Strengths: This can be a gentler form of introductions where rats are not strongly hierarchy driven, it can also be useful for ill and infirm rats who need more supervision and protection during introductions.
Weaknesses: Masking a rats natural smell can cause some rats to feel the need to establish themselves more, this is particularly true of those lacking self-confidence, I would avoid this unless it is clearly needed. Repeated introductions and then separations can elevate stress levels, particularly in buck groups, though it does depend on the individuals involved. These allow the rats to know that others are present but not resolve the hierarchy question. In some rats this can increasingly wind them up, making each subsequent introduction harder so if each session is getting harder stop this method and try a different one. It also does mean a longer period of introduction, with rats that have chronic illnesses that are affected by stress it may be worth going to a faster method and covering them with antibiotics.
Hints and Tips: Try and have some food hidden around the neutral space as well as interesting objects (but not enclosed), this can help distract the rats. Scatter fed food can add to this distraction but avoid feeding in only one bowl (unless its big enough to fit all the rats in) or putting only a few bits of food in that could be fought over. If this is going well on the first meeting it may be worth jumping straight into the carrier method rather than separating them again. An alternative to adding a smell to the rats is to bath them all, in addition to altering their smell this also puts them through a stressful event prior to introductions which can put them in the same frame of mind, and take the edge off any dominance behaviours. In many cases neither of these are necessary. In some cases it is worth standing well back from these intros unless needed to intervene as rats can get possessive over there humans.
Why: a neutral space belongs to no one so they do not feel the need to defend as hard (reducing the intensity of the fighting), repeated introductions build familiarity without allowing it to escalate, all rats are in the same situation creating an equal platform to build the group from, all rats smell similar (meaning it is less easy to distinguish newcomers)
Strengths: This can be a gentler form of introductions where rats are not strongly hierarchy driven, it can also be useful for ill and infirm rats who need more supervision and protection during introductions.
Weaknesses: Masking a rats natural smell can cause some rats to feel the need to establish themselves more, this is particularly true of those lacking self-confidence, I would avoid this unless it is clearly needed. Repeated introductions and then separations can elevate stress levels, particularly in buck groups, though it does depend on the individuals involved. These allow the rats to know that others are present but not resolve the hierarchy question. In some rats this can increasingly wind them up, making each subsequent introduction harder so if each session is getting harder stop this method and try a different one. It also does mean a longer period of introduction, with rats that have chronic illnesses that are affected by stress it may be worth going to a faster method and covering them with antibiotics.
Hints and Tips: Try and have some food hidden around the neutral space as well as interesting objects (but not enclosed), this can help distract the rats. Scatter fed food can add to this distraction but avoid feeding in only one bowl (unless its big enough to fit all the rats in) or putting only a few bits of food in that could be fought over. If this is going well on the first meeting it may be worth jumping straight into the carrier method rather than separating them again. An alternative to adding a smell to the rats is to bath them all, in addition to altering their smell this also puts them through a stressful event prior to introductions which can put them in the same frame of mind, and take the edge off any dominance behaviours. In many cases neither of these are necessary. In some cases it is worth standing well back from these intros unless needed to intervene as rats can get possessive over there humans.
How to use it
1, Start off with the rats in 2 carriers or cages, make sure you have a towel or water spray bottle on hand in case anything goes wrong. Next pick your neutral space. This should ideally be big enough that they can move around and explore, but not so big that the rats can completely avoid each other. A table top in an unfamiliar room, a sofa, a bed covered in a large fleece rug or even the bath with a towel placed on the bottom (it can be very slippy otherwise and can scare the rats) work very well. You can add a few interesting items, such as bits of rock, cardboard to chew, some wooden chew toys or similar, just don’t add anything enclosed, such as a tunnel, or most importantly something enclose. As with the carrier intro take the rats into a room that the rats don’t normally free range in which has a small neutral rat safe space in it (table top, couch, bed or bath with a towel down) and add the rats to this neutral space. Where you have a strong, confident Alpha, add them and the newcomers first. Once he is settled then add the calmest rat in your group, going from those you think will be the easiest to intro, to those you think will be hardest, one rat at a time. This doesn't overwhelm the newcomers as quickly and also with the Alpha being happy with them to start with he will often intervene if any following rat takes things too far.
A certain amount of fighting or minor scuffles are normal and helpful, you should expect pinning, heavy grooming and some chasing around and maybe some boxing. You may also get squeaks and pitiful wails, let them do this, interrupting them will stop them working out whose boss. Look out for the truly aggressor poofing up (hedgehog impression) or sideling (walking sideways towards the other rat, head lowered, possibly tail swishing or chomping his teeth), this is overly aggressive behaviour and can lead into a bite, don’t separate straight away, try distraction with a loud noise or blowing on them. The idea is to prevent any damage but not stop perfectly natural battles which will let them know there position in the hierarchy, the general rule of ‘No Blood, No Foul’ is a good one to bear in mind. Once things have quieted down and the existing rats are ignoring them (at this stage they are probably cowering in the corner) then add another rat, and so on, once they are all added move on to the next step. Note: This behaviour may, and probably will, occur at any step of the process, the same rules apply.
2, Once the rats are mainly ignoring each other and exploring for a while you can relax a little bit. Give them a good hour or two, ideally long enough that they become tired and settle down somewhere. If the scuffles start turning into more full on aggression that won’t be disrupted or a rat is visibly getting worked up then you may choose to end the session early to give them a break. Once the play time is over put them back in their respective cages. Repeat this at least daily, a couple times a day can also work well making sure they have time to rest, eat and sleep in between. If you notice that each time you do these introductions the rats are getting more stressed stop using this method, give the rats a week or two to calm down and then try a different method. This could be a sign that repeated introductions and separations is increasing rather than lowering stress levels.
3, Once the rats are routinely ignoring each other or even better interacting in a relaxed low stress manner then you need to move onto a smaller space based approach, this can be the carrier method; starting small and moving up, or you could choose to move the rats straight into their eventual cage. If you choose to go this route then make sure that the cage is very neutral to start with, deep clean it and ensure that toys are either new or have been well washed. Also make sure that there are no dead ends or small places like tubes that can be fought over.
A certain amount of fighting or minor scuffles are normal and helpful, you should expect pinning, heavy grooming and some chasing around and maybe some boxing. You may also get squeaks and pitiful wails, let them do this, interrupting them will stop them working out whose boss. Look out for the truly aggressor poofing up (hedgehog impression) or sideling (walking sideways towards the other rat, head lowered, possibly tail swishing or chomping his teeth), this is overly aggressive behaviour and can lead into a bite, don’t separate straight away, try distraction with a loud noise or blowing on them. The idea is to prevent any damage but not stop perfectly natural battles which will let them know there position in the hierarchy, the general rule of ‘No Blood, No Foul’ is a good one to bear in mind. Once things have quieted down and the existing rats are ignoring them (at this stage they are probably cowering in the corner) then add another rat, and so on, once they are all added move on to the next step. Note: This behaviour may, and probably will, occur at any step of the process, the same rules apply.
2, Once the rats are mainly ignoring each other and exploring for a while you can relax a little bit. Give them a good hour or two, ideally long enough that they become tired and settle down somewhere. If the scuffles start turning into more full on aggression that won’t be disrupted or a rat is visibly getting worked up then you may choose to end the session early to give them a break. Once the play time is over put them back in their respective cages. Repeat this at least daily, a couple times a day can also work well making sure they have time to rest, eat and sleep in between. If you notice that each time you do these introductions the rats are getting more stressed stop using this method, give the rats a week or two to calm down and then try a different method. This could be a sign that repeated introductions and separations is increasing rather than lowering stress levels.
3, Once the rats are routinely ignoring each other or even better interacting in a relaxed low stress manner then you need to move onto a smaller space based approach, this can be the carrier method; starting small and moving up, or you could choose to move the rats straight into their eventual cage. If you choose to go this route then make sure that the cage is very neutral to start with, deep clean it and ensure that toys are either new or have been well washed. Also make sure that there are no dead ends or small places like tubes that can be fought over.