Many aquarists encounter some sort of nuisance animals at some point. Whether it is snails in freshwater or shrimp, worms or the errant troublemaking fish in saltwater, trying to remove the offender can be difficult. While there are traps galore available for sale, you can also make your own at home if you need a quick trap. This kind of trap is effective on things like Mantis Shrimp, Pistol Shrimp, freshwater snails and other small inverts and can be made from items you probably already have in your home.
How its made
- Plastic soda or water bottle – the 16-32 oz sizes usually work.
- Scissors or box cutter to cut the bottle
- Superglue, hot glue gun, fishing line and/or stapler
- Bait – shrimp or scallop for the meat-eaters or scavengers, zucchini or macroalgae for the plant-eaters
Start by prepping the bottle you are using. Remove any labels, lids, or extra pieces and clean it out really well. You can rinse it thoroughly in hot water but try to avoid using any soaps that might not rinse out completely. Next, cut the top off of the bottle just below or at the widest point of the top. Invert the top piece into the bottom so the narrow opening points into the bottle and you’ve formed a “funnel” on the top. Now you will need to attach the two pieces together. Depending on the plastic material, you can use Superglue or a hot glue gun, or you can even “sew” the two pieces together with strong cord or fishing line and a sharp needle. I prefer a hot glue gun personally since the glue is thicker and sets as soon as it cools. For short-term traps, you can also staple the two pieces together, but keep in mind that metal rusts so stapled traps should not be used long-term.
Once the glue is dry, you can insert your bait and your new trap is ready to go. If you are targeting something like a pistol shrimp or Mantis Shrimp in a burrow and you know where the burrow is, position the trap so the opening is facing the burrow. With snails in planted tanks, you can position the trap anywhere convenient in the aquarium. If an air pocket gets stuck in the bottle, you can cut a small “vent” slit in the bottle with your blade.
How it works
Ideally, your targeted “prey” enters the trap through the funnel you created but has difficulty exiting through the narrow entrance it first came through with the sharp sides you’ve made. For animals that crawl, traps like this are normally effective. For swimmers, it can be less effective since they can swim up to the opening but it may confuse them just long enough for you to “harvest”. Once your prey has entered, remove the trap and remove the nuisance!
Keep in mind that snails in freshwater and bristleworms in saltwater feed on nutrients and reproduce quickly; trapping them will not eliminate big outbreaks if they have a lot of food to feed on and continue to grow. This kind of trap is a good quick-fix but if you decide to keep trapping or your prey isn’t falling for it right away, there are many professional traps on the market that operate under a similar principal.