Weird category editing 100s of sites removed

[powerofeyes]

When I was browsing dmoz recently I saw a weird editing in a category, More than 100 sites have been removed and 10 new sites have been added, Those 10 new sites doesnt look worth to be listed there,

See this category,

http://dmoz.org/Shopping/Pets/Supplies/

Compare the 2 results,

http://dmoz.org/Shopping/Pets/Supplies/

http://directory.google.com/Top/Shopping/Pets/Supplies/

The above category is a very important category in dmoz and 1000s are sites are competiting to get a listing there, So what is happening anyone can guess, weird :confused:

Edit reason - Got an answer from Resource-zone.com
Answer from meta:

If a category gets a lot of listings we can decide to split it into smaller parts. As has been done here. Compare the 2 results given by you and now look at all the subcategories.

[smindsrt]

Moving sites around is done ALL THE TIME, as well as adding new categories.

Sometimes it for the better and sometimes it's just confusing.