| intestinal helminths infection of rats (ratus norvegicus) in the belgrade area (serbia): the effect of sex, age and habitat. | summary: gastrointestinal helminths of norway rat (rattus norvegicus) from the belgrade area were studied as a part of a wider ecological research of rats in serbia (data on the distribution, population ecology, economic and epizoothiological-epidemiological importance, and density control). rats were captured from may 2005 to july 2009 at both urban and suburban-rural sites. of a total of 302 trapped rats 48% were males and 52% females, with 36.5% and 38.8% of juvenile-subadult individuals, per ... | 2011 | 21678796 |