The Cub Scout pack is broken down into smaller groups called Dens.  Scouts work on different ranks based on their ages.  They learn new skills and build upon those skills to meet new challenges as they get older and advance through the Cub Scout program.
Lion Cubs are our youngest scouts, in kindergarten.  Lion Cubs serves as a fun, family-oriented introduction to Cub Scouting.  Lion Cubs attend one den meeting and one "Grand Adventure" each month.  Lions are encouraged to attend pack meetings and events.
Bobcat is the first rank that all scouts complete prior to receiving the rank for their age.  Lion Cubs begin working on their Bobcat requirements after they graduate to the Tiger Den in the spring of their kindergarten year.
The Tiger Den serves first-graders who attend meetings and activities with their adult partner, and work together to complete the requirements of the Tiger Cub badge.
Second-grade scouts form the Wolf den.  They attend den meetings on their own, but continue to work on the requirements of their Wolf badge with their families.
Third graders form the Bear den.  Family involvement is still needed to complete the requirements for the Bear badge, but scouts have more choices in their activities and have enough knowledge and skill to take on more of the requirements by themselves.
Fourth graders become Webelos Scouts.  These scouts complete more advanced activities for their Webelos rank. The Webelos and Arrow of Light requirements can be met at any time in fourth or fifth grade.

 In fifth grade scouts work on Arrow of Light requirements. The advanced activities help prepare boys for their graduation into Boy Scouting, typically in February at the Blue and Gold banquet.