southern part of the province. Frogs and salamanders are a few of the amphibians that make their homes in Alberta. Alberta is the only province in Canada—as well as one of the few places in the world—that is free of Norwegian rats. Since the early 1950s, the Government of Alberta has operated a rat-control program, which has been so successful that only isolated instances of wild rat sightings are reported, usually of rats arriving in the province aboard trucks or by rail. In 2006, Alberta Agriculture reported zero findings of wild rats; the only rat interceptions have been domesticated rats that have been seized from their owners. It is illegal for individual Albertans to own or keep Norwegian rats of any description; the animals can only be kept in the province by zoos, universities and colleges, and recognized research institutions. In 2009, several rats were found and captured, in small pockets in southern Alberta, putting Alberta's rat-free status in jeopardy. A colony of rats was subsequently found in a landfill near Medicine Hat in 2012 and again in 2014. Paleontology Alberta has one of the greatest diversities and abundances of Late Cretaceous dinosaur fossils worldwide. Taxa are represented by complete fossil skeletons, isolated material, microvertebrate remains, and even mass graves. At least 38 dinosaur type specimens were collected in the province. The Foremost Formation, Oldman Formation and Dinosaur Park Formations collectively comprise the Judith River Group and are the most thoroughly studied dinosaur-bearing strata in Alberta. Dinosaur-bearing strata are distributed widely throughout Alberta. The Dinosaur Provincial Park area contains outcrops of the Dinosaur Park Formation and Oldman Formation. In Alberta's central and southern regions are intermittent Scollard Formation outcrops. In the Drumheller Valley and Edmonton regions there are exposed Horseshoe Canyon facies. Other formations have been recorded as well, like the Milk River and Foremost Formations. The latter two have a lower diversity of documented dinosaurs, primarily due to their lower total fossil quantity and neglect from collectors who are hindered by the isolation and scarcity of exposed outcrops. Their dinosaur fossils are primarily teeth recovered from microvertebrate fossil sites. Additional geologic formations that have produced only a few fossils are the Belly River Group and St. Mary River Formations of the southwest and the northwestern Wapiti Formation, which contains two Pachyrhinosaurus bone beds. The Bearpaw Formation represents strata deposited during a marine transgression. Dinosaurs are known from this formation,