source: On occasion the male "den master" will also allow a second male into the den; the reason for this is unclear.
target: On occasion the male "den master" will also allow a second male into the den. The reason for this is unknown.
references: On occasion the male "den master" will also allow a second male into the den. The reason for this is unknown. Sometimes the male "den master" will allow a second male into the den, but no one knows the reason for this. Sometimes, for unknown reasons, the male "den master" will also allow a second male into the den. Sometimes the male "den master" will allow a second male into the den. It is unclear why, but occasionally the male "den master" will allow a second male into the den. Sometimes the male "den master" will also allow a second male into the den.  The reason for this not clear. The male "den master" allows a second male into the den occasionally. Sometimes, the male "den master" will allow a second male into the den. Sometimes,  the male "den master" will also allow a second male to get into the den; although the reason for this is not clear. The male den master will let a second male into the den but it is not known why.