list in list

• mammals

1. dog
   1. collie
   2. dashshund
   3. poodle
2. cat
   1. persian
   2. calico
3. pig

• fish
  1. trout
     1. brown
     2. rainbow
     3. brook
  2. gold
  3. sword

• insects
  1. ant
  2. grasshopper
  3. fly

• birds
  1. blue
  2. eagle
  3. quail
  4. robin