Updating animals

Which type of animal updates regular ?

I have 2 sea turtles (Splash and Madame Leota) and those update every day. Only 1 day that neither updated.

I have 2 elephants (Orchid and Naisula) and neither have updated since the 12th.

I have a shark (Mia) and no update since 10th.

I also have a giraffe (Fowsio) and no update since the 10th.

Is it just my animals that aren't updating? What other animals are updated more often?