Jennifer- a pooter (sometimes also called an aspirator) is a device for collecting small invertebrates by sucking them up. Usually the sucking power is provided by the user's mouth.
The way to make one by my method is to take two pieces of siphon tubing (one long one for the inlet, one shorter one for the mouth tube), two short (ca. 2 cm) pieces of thick-walled rubber tube, a small square of netting (about 2cm square), and a small glass jar with a tough plastic lid.
The rubber tube must be just big enough to fit the siphon tubing through it.
Make two holes in the lid, slightly smaller than the diameter of the rubber tube (this is important, everything must be tight), then push the rubber tubes halfway through each one.
Then push the siphon tubes through those (this should be quite hard to do, it must grip well), having first wrapped the netting round the mouth tube (this is important, too, else you'll be eating the insects yourself).
Then you can screw the lid onto the jar, and suck small insects into it (a quick, sharp suck is best, I find). When you want to get them out to feed to your animals, just unscrew the jar again.
Mine works for insects up to the size of medium crickets, but it's particularly handy for fruit flies. Obviously it wouldn't be a good idea to suck up anything from particularly unsavoury places- I understand some entomologists use vacuum pumps to power pooters for this purpose. Pooting from dusty places can be quite unpleasant, too...
I've just uploaded a picture here:
http://www.darkwave.org.uk/~caleb/pix/temp/pooter1.jpg
and a closeup of the lid here:
http://www.darkwave.org.uk/~caleb/pix/temp/pooter2.jpg
