Reinigen

A Reinigen (plural: Reinigens; pronunciation: RY-ni-gin; Germ. reinigen "to clean") is a rat-like Wesen that exist at the bottom of the Grimm creature food chain, despite this, unlike fellow rodent wesen Mauzhertz, they have no known natural predators.

Biology
When Reinigen woge, their eyes become darker, their ears become larger, their faces become pointy, and their incisors enlarge.

While they are no stronger than an ordinary human, Reinigen are quick and light on their feet, as Roddy was able to out run Nick Burkhardt for a few seconds before the latter caught up. They also seem to have greater endurance and durability, as one Reinigen was able to jump up and attack a bystander after just crashing their car, following which it ran through a glass door, and despite being injured, proceeded to wreck an entire office without stopping. They can also resist the effects of Fluvus Pestilentia for much longer than other Wesen, such as Fuchsbau and Stangebar.

Reinigen, or at least some of them, have incredible potential when it comes to music. They are able to utilize these abilities to mesmerize and control rats, similar to the way Mellifers control bees. These abilities however may only be found in a select few Reinigen as Ephram Geiger considered his son Roddy to be a prodigy.

Behavior
They are similar to rats in that they are scavengers, not being the least bit picky about what they eat. They appear to be peaceful creatures like their fellow rodent Wesen, Eisbibers and Mauzhertz, and Stangebärs, but unlike them (except Stangebärs), Reinigen are nowhere near as meek or cowardly. Still, they are very cautious in the presence of stronger Wesen, as seen when Roddy backed away from Monroe after realizing Monroe was a Blutbad. Despite being cautious and generally non-violent, Reinigen can be very temperamental especially if they have a history of being treated poorly. Although normally non-violent, they will resort to violence if pushed to their limits, as their tempers can get the best of them.

Reinigen also appear to have an affinity for actual rats, for example Roddy's father, despite being an exterminator, preferred to capture and release rats, rather than kill them.

Monroe described them as being "at the bottom of the food chain" and hints at them living on the leftovers of society.

Like many Wesen, Reinigen fear Grimms, however they are not terrified of them, merely wary in their presence.

After a high school teacher is murdered, the case leads to two Reinigen: Roddy Geiger, a violin prodigy, and his father.

At least one Reinigen infected with the yellow plague died from gunfire while attacking police officers.

Excerpt from Grimm Diaries
(By Nick Burkhardt) December 8, 2011

"I've encountered a young boy and his father living as Reinigen and running a pest control business. The young boy is extremely gifted with the violin but is also very troubled. His father is moody and on edge, probably as a result of years of disrespect at the botton of the Grimm creature food chain.

''I've learned from a trustworthy Blutbad that these rat-like creatures are rarely violent unless pushed to the limit. They apparently possess a musical ability that enables them to mesmerize and control the rat's behavior, similiar to the tale of the Pied Piper. While I don't believe these creatures pose a direct threat to me, they have proven uncooperative and are difficult to deal with."''