a launch-rod attached to a metal plate. Cannon propellant is smokeless gunpowder ignited by an electric match. The primary advantage of cannon nets is the lack of explosives, therefore storage and transportation is easier. However, cannon-net projectiles have to be cleaned after every use. A full-sized cannon-net may utilize four or more cannons to pull the net over the target birds. Smaller nets with fewer cannons may also be used. Air powered cannon The Martin Engineering Net Blaster is a similar device that propels a weight attached to a rocket net via a rope without the use of explosives. The Net Blaster was developed between researchers at USDA APHIS Wildlife Services and Martin Engineering as an alternative to the rocket net where the use of explosive charges would not be advisable, such as capturing oiled birds at an oil spill. The Net Blaster is charged with a portable compressor and set out in a similar fashion to the rocket nets placed in boxes. The air powered cannon is much quieter than rocket nets, but are much more expensive and less powerful. Use The rocket net or similar-looking item is placed at the target location after days or week of pre-baiting the target species in, or is place in an area where it is likely to capture the target animals, to allow animals to become accustomed to its presence. When the biologist is ready to use the actual rocket net, the net is folded accordion style in a line or packed in the rocket net bock. The rear or trailing edge of the net is staked to the ground by ropes and the leading edge of the net is attached to a number of rockets (typically 3 or 4) via longer ropes. The rockets are placed on the box, staked to the ground, or placed on post for additional elevation when taller animals are trapped. The charges are placed in the rocket and the wires attached to a shunted electrical blasting line. Once all the charges are connected, the line is tested, and the area is safe, it is attached to the capacitor blasting machine. When the animals are in place, the operator activates the blasting machine and the electrical charge ignites the rockets, propelling the net over the animals. The biologists and their team then remove the animals for whatever study they are conducting. Catching waders When cannon-netting is carried