Mike,

I've found that drainage tubes work great and cost a fraction of
"ferret" tubes. The ones I bought were in Home Depot. They are sold
to provide drainage to land and come in several diameters. They are a
thick plastic and about 7 feet in length. Be sure to get the ones with
holes along the length so air can get in. If I remember right the last
one I got (about 3 years ago) only cost about $4. Another advantage is
that they also have various connectors so you can build a maze and
change the layout to keep them interested.

Matt Claus

[Posted in FML 5995]