Are These Two Rats’ Behaviors “Over the Top”?

The Triage list? Scroll down - under the first video on this page is a list of key issues to consider when thinking about how two rats are interacting.

DISCLAIMER:
This information is for educational purposes only and cannot be used to diagnose whether two rats might erupt in aggressive behavior, and cannot be used to prevent injury. Separate your rats if you are unsure of their behaviors.
Seek help to evaluate your rat's behaviors and potential for aggression.
You have everything to gain by separating rats. You have everything to lose if you don't separate them and one rat then attacks another. One rat can slice open the insides of another rat faster than you can blink.
Please please keep your rats safe.

Read more and study videos of rats relating to each other:
Establishing the Social Hierarchy: Normal Rat Behaviors
Major Rat Body Language - RattyRat
Submission, Dominance, Appeasement
Normal Play Behavior in Rats - YouTube
The Dangers of “No Blood, No Foul”
Aggressive Rat Behaviors During Intros
Techniques to Introduce Rats
Rat Introductions YouTube

Without having extensive information about the rats in the above video, I see:
(1) Youngish rats, (2) in an open, apparently neutral area,
(3) Three rats taking turns bouncing, chasing, pouncing, each other, with no blood drawn at any time,
(4) The behavior gets more intense inside the house - where I cannot see just how intense it gets,
(5) Yet the behavior continues after the box without worsening or increasing in intensity,
(6) The behaviors continue in all areas, without any others resource visible, for the most part, except the house,
(7) None of the rats become piloerect (poofy), and (8) They can stop the behaviors (stop and start).

What would this information mean? Read on below.

The owner's comments about what was going on in this video can be found under the triage list next. How did I do?

Triage List of Questions to Assess Two Rats’ Behaviors:

First, if blood is being drawn, separate the rats. If you are seeing poofy, separate the rats. If you are not sure what you are seeing, separate the rats. Aggression can lead to fatal injury — there is much wisdom in “better safe than sorry”.

Below is a kind of triage list of questions to run through to help assess such behavior.

Some history-taking first:

1. Age and sex of each rat? Are they all intact?
2. Was blood drawn? Has blood ever been drawn?
3. Are these bonded cagemates, or are they new rats to each other and this is an introduction session?
4. If they are bonded cagemates who were introduced to each other, how long have they lived together, how long did the introduction process take? Where there any aggressive incidents?
5. If they are in an introduction process, how many sessions have they had together so far, and what baby steps have taken place prior to this (like cage swapping)?
6. Does this involve a dramatic change in behavior for any of the rats, which might indicate a disease process, illness, or pain. In this case if there's any suspicion I would see a vet.

Assuming there isn't illness, with the above information:

1. Age will tell us if they're babies where play behavior might explain and predominate.
2. Intact or not, along with age, will tell us if hormones are kicking in at about 5-8 months of age, or even later. This could explain what might be new or escalating aggressive behavior, and neutering may be needed.
3. If this is an introduction session, knowing what steps have come before can help us figure out if the intro process has been rushed, or is just beginning. These will help us determine if the new behaviors are verging on problematic aggression.
4. If blood is drawn, this tells us there is aggression that has gone overboard for some reason and separation is important right now, until the reason for the behavior, and a solution, can be found.
5. If none of the above are relevant, and if these are bonded cagemates, young ones or adults — on to the next set of questions.

With the above issues sorted out to the extent possible, now we can think about bonded young adult, or adult, cagemates:

1. Is there a resource present? Dominance behavior is always about a resource, where a resource is any object. Or even a location! It's up to the rats as to whether some thing is a highly valued, or scarce, resource. Examples include food, treats, the box, the hammock, the special corner of the cage, the opening to the tunnel, the side of anything (as opposed to the non-side of something). Watch the behavior and look for any nearby thing, space, or object that the rats might want to occupy, steal, eat, dig into, block, sleep on, etc.
2. If there is a resource, so that dominance and submission are at play, we would see this pattern: One rat tries to take that special something (dominates), and another rat tries to hold on, or gives it up (submits), with more or less intensity on both sides. The behaviors generally don't end in injury. Dominance involves an interchange between two rats at a time. All rats may be dominant and submissive at different times, about different resources. We would normally see all rats being both submissive and dominant at various times. Over time we might also see a social hierarchy (also always about dominance over resources) where some rats are more dominant more often in some situations.
3. When all is said and done, bonded cagemates stay bonded. After the behaviors you're trying to assess, do the rats calm down, can they be around each other peacefully, do they sleep together as normal. If one rat is constantly looking intimidated, or hiding, or looks very stressed, then there may be an imbalance in some relationship.
4. If there isn't a resource present, and there isn't aggression, we may be seeing play. Play can involve more than 2 rats at a time. Pouncing, following, stopping, starting, sidling, relenting, charging, chasing. Even flipping upside down, squeaking, boxing, sidling, can be play behaviors. The rats are able to stop themselves, or one rat can pull out.