Justin Bieber slammed over pet monkey, Mally

Justin Bieber is acting like an animal, at least according to animal rights activists.

The Humane Society of the United States has labeled the 19-year-old "out of control" for having a pet monkey. Mally, the Biebs' capuchin, reportedly a 19th birthday present, is currently in quarantine in Germany after the "Boyfriend" singer reportedly tried to bring her into the country through Munich Airport last week without appropriate documentation.

Officials have told the Canadian pop star he has four weeks to show them his papers.

"If he doesn't, Mally will be taken to a good animal shelter that has experience rearing groups of young capuchin monkeys and can ensure disoriented Mally becomes a healthy little capuchin," the shelter quarantining Mally said.

Bieber who is currently continuing the European portion of his Believe tour, also reportedly faces $16,000 in fines for breaking import laws.

But the Humane Society is more concerned about the fact that the Ontario native is setting a "bad example" by having a pet monkey at all. The shelter was reportedly forced to give Mally, who is said to be around 14 weeks old, veterinary care as she appears to have been taken away from her mother too early.

“No primate species should ever be kept as a pet. They have very special needs," said Debbie Leahy, manager of captive wildlife protection for the Humane Society. "These are highly social animals. They need to be kept with others of their own kind; that’s just critical to their psychological well-being."

She added that primates "can become aggressive" and may turn on their owners.

But this isn't the first time the Biebz has had a wild animal in his care. Remember his pet boa constrictor Johnson? He used the animal as his date for the 2011 MTV Video Music Awards then auctioned it off last year for $1,000, with the proceeds going to his charity, Pencils of Promise.

"I found it really disgusting that celebrities like Bieber would stoop to a level of using living creatures as a fashion accessory and then so easily discard it," winning bidder Michael Kronick told E! News before donating the animal to the Reptile & Amphibian Discovery Zoo in Owatonna, Minn. "I wanted to make sure the snake would be well taken care of for the rest of his life."

The Biebs' also gave away his pet hamster last year. He reportedly unloaded PAC and his cage on a teen girl from Atlanta after his Jingle Ball concert. Unfortunately, the hamster fell ill earlier this year and died last month.

Hmmm, we're starting to think Bieber might want to take a break from animal rearing.

(photo via Justin Bieber's Instagram)