It’s important to spend time with your rats every day so that you can recognize any abnormal anti-social behavior. If one of your pets seems unusually listless, shows little interest in food or isolates himself from the rest of the pack, then there is probably something wrong with him. Get help from a veterinarian that specializes in small mammals as soon as possible.

What does it mean when...?

Rats Grinding Their Teeth

Rats grind their teeth when they’re happy. This behavior is called bruxing, and it is often compared to purring in cats. You may not notice this soft sound at first unless your rat is perched on your shoulder at ear level. Once your rat gets going, it may seem as if the vibration generated by his grinding teeth carries through his entire body, causing him to shake all over.

Eyeball Vibrates (rapidly in and out of the socket)

Boggling occurs during high-intensity bruxing (soft, repetitive grinding of the incisors). Usually considered to indicate pleasure and contentment.

Body Shakes (like rat is cold)

Buzzing is also like purring to a cat.  Usually considered to indicate pleasure and contentment.

Rats Teeth Chatter

Chattering indicates that a rat is angry at another rat.  It should tell you whether or not he is distressed. If the hair on his back is standing up or if your rat’s whole body is stiffened and alert, eyes steely and focused, then he is likely upset. A rat may make screeching or hissing sounds when he is confronted or attacking another. If your rat shows signs of anger or acts viciously toward another rat in the colony, separate him from the group and give him time to calm down before you reintroduce him to the cage.

Stands on Back Leg.

Playful posturing is a regular part of the rat social hierarchy. You’re most likely to witness dominance drama when you introduce a new rat to your colony. After a sniff-over and a brief wrestling match, the less-dominant rat in a new pair may end up pinned on his back on the floor. He should suffer no serious injuries, save injured pride. The squeaks and squeals you hear from your rats when they’re sparring playfully like this are indignant protests (“Hey!”) rather than shrieks of distress. Separate your rats if one bites another hard enough to make him bleed.

Female Vibrates Ears Rapidly

Ear wiggling is part of a suite of solicitation behaviors in which the female initiates and maintains mounting behavior by the male. Ear wiggling occurs when the female is in heat, about every 4-5 days.

Rat Wags Tail

Rats may wag or writhe their tails on the ground. This action has many names, such as tail wagging, tail swishing, and tail writhing. Tail wagging may involve the whole tail or as little as the tail tip.

The function of tail wagging is unknown in rats, but it appears to be associated with excitement and tension. For example, rats may writhe their tails during aggressive encounters with each other, or when facing a predator.

Sways Head from Side to Side (looks as if rat is drunk)

Some rats, especially pink eyed albinos, often sway from side to side. Albino rats have extremely poor vision, and this swaying may help them see better. Dark-eyed rats may sway or bob their heads up and down too, though they tend to do so less frequently than albino rats. Head bobbing in dark-eyed rats is usually seen before the rat takes a big jump.

Swaying may help the rat figure out how far away various objects are. When a rat moves its head, the images of the objects around the rat move across its retina. Close objects will move faster than far ones, a phenomenon known as motion parallax. Rats may use such motion marallax cues to judge distance and depth.

One Rat Grooms Another Rat's Belly

Belly-groom or power grooming may be an attempt to reach the nape, which is the goal of play fighting.

Belly-up roll (pin): Juvenile-type defense tactic in which one rat rolls onto his back before another, sometimes after receiving a nip or bite on the rump. The top rat may then step on the supine rat, sometimes orienting himself perpendicular to the long axis of the supine rat (thus avoiding the whiskers), and pinning him down. The top rat may groom the supine rat's belly (see also belly-groom, or power groom, perhaps as an attempt to gain access to the nape or rump. Rolling on one's back tends to prevent further attack for several reasons: play fighting is directed at the nape, and serious offensive bites are directed at the lower back and flanks, so a roll hides these areas. Also, the rolled rat becomes motionless, and motion is an important stimulus for attack (Thor et al. 1981). Lastly, the recumbent rat may track his opponent's face with his teeth and whiskers, which may actively inhibit attacks as well (Blanchard and Blanchard 1977).

So, the belly-up roll is probably not a signal of submission or defeat that inhibits further attack, because the attaker may continue to press his attack. The belly-up roll is instead a defensive strategy: the subordinate rat can escape being bitten insofar as he can interpose his belly between the attacker and his own vulnerable target areas of rump and nape.

One Rat Kicks Another

Kicking may occur when a sidling rat approaches another very closely. The hind foot closest to the second rat kicks out, and may contact the second rat on the flank or higher on the the back.

Offensive kick: The rat's offensive kick looks more like a hind-foot grab which pulls the two rats into a close encounter, perhaps enabling the kicker to position himself just prior to a fight.

Defensive kick: The rat raises a hind foot and uses it to keep off or push away another rat

Refer to:  http://www.ratbehavior.org/Aggression.htm

Rat Pees Everywhere

Urine marking/Scent marking: The rat deposits tiny droplets of urine on the surfaces and objects he walks on. Considered an advertisement of the rat's presence and a sex attractant. Urine may be deposited by: (1) anogenital drag: rubbing hindquarters over top of object, leaving a trail of urine as the rat steps over it; or lifting hind leg nearest the object and urinating on one corner while standing, or walking beside the object with one hind foot on top of it, leaving a trail of urine along the entire length of the object (Brown 1975). Rats may urine mark each other by crawling over another one. Refer to: http://www.ratbehavior.org/WhyDoRatsPee.htm

Rat Scraps/Rubs His Front Paws on the Ground

This seems to be sort of a scent-marking or territorial gesture. I have observed that rats that do this seem to be unusually territorial. Some rats will also rub their sides along objects. I believe that these two behaviors are connected and occur for similar reasons

Rat Licks or Nibbles Hands or Skin?

Your rat is displaying grooming behavior towards you. I think rats treat their human companions as if they (the humans) were large rats. I believe that by doing this they are showing that they care for you.

Also rats like the salty taste of sweat and if you are sweaty or have some food residue on you they will be enthralled with the prospect of grooming you. Also males particularly will grab your hands and sniff intensely as if they wanted to inhale your skin if you have been touching/holding a female rat.

Barber:

Excessive grooming in which the fur is nibbled off. Rats may barber each other, in which case frequent areas of barbering and subsequent bald spots on other rats are the head, face, neck and shoulders. Dominant rats may barber subordinates (e.g. Bresnahan 1983).

Thanks for the following websites:  http://www.ratbehavior.org/ and http://www.greeneyedesigns.com/Rats/bodlang.html and

http://ratguide.com/health/integumentary_skin/dermatophytosis.php (ringworm)