Select_tag with options_for_select not populating DB.

I'm trying to get my animal app to let users populate info about each
animal. The code below partially works. It shows the drop down menu,
and it shows the names of what I wanted it to be the names of the
Databases. I don't know how to make it work so it shows the name dog
and than you hit submit and it appears in the dog view. When I hit
submit it just makes a new view under the current database, when I
want it to change to the one selected.
I changed variables and instances for privacy reasons(I'm sure most
people do.)
<% form_for :animals do |f| %>
<%= f.error_messages %>
<%= f.label :update %>
<br />
<%= f.text_area :updates, :rows => 6 %>
<br />
<%= select_tag "update", options_for_select(%w{dogs_info
feline_info}) %>
<%= f.submit "submit" %>
<% end %>

I really appreciate any help!
Thank you.