The problem with foil is that it is not particularly
sticky, so if you approach the construction of the
armature as you would a wire sculpture, you should
have more suceess. Here's what I mean:
1. Form an anchor shape, in the case of an animal,
the oval body, first.
2. Use a strip of foil to form legs that contains
enough foil to make two legs that are connected.
Drape the foil across the anchor shape and crush the
foil into the folds of the body to hold it while
shaping the legs.
Repeat this with the back legs.
3. Using the draping and crushing technique, form a
neck and head out of one piece of foil and anchor that
to the sculpture. Repeat this with the tail.
The trick of using foil is to not use pieces bigger
than kids can handle, making sure all pieces are
firmly anchored before going on to the next part, and
making as few parts as possible to prevent loose
elements. Any taping should always glue tape to tape,
not tape to foil--it doesn't work too well and is
likely the source of your pieces falling apart. You
might also try buiding a pipe cleaner armature and
crush the foil to that.