The pest management group at Nga Manu Bird sanctuary has had ongoing issues with bait loss from mouse and rat traps. Slugs have been identified as the chief culprit as occasionally they set the trap off and are caught. We have developed small ventilated bait caps that slip over the bait, preventing access by slugs and snails but still able to emit a odour as a lure. These appear to be very effective in preventing bait loss and also do not appear to impact the kill rates for target pests. The caps can be 3D printed and I’m happy to share the STL file with anyone wanting to give them a go.
Here is a picture of the cap installed into a mouse trap. Larger caps fit the rat traps of similar design:
(https://photos.app.goo.gl/cu9qaexMKrz2whio7)
Fortunately, I rarely have any trouble with slugs or snails, but there are several things that might work for the sanctuary that have been effective at reducing lure loss to rodents where I trap.
In mouse traps with a circular bait cup, a chickpea can be pressed on top of a sticky base lure. The gap between the edge of the bait cup and the chickpea is quite small, so only small slugs or snails could reach the base lure. Chickpeas are very dry and very hard, so slugs and snails won’t be able to eat them, and mice either attempt to remove the chickpea or nibble on it in the bait cup. Either way, mice create more movement on/in a trap than they would with an exposed lure. A chickpea can last in a trap for a remarkably long time, because a mouse is usually trapped when they’ve only nibbled a small % of the pea. In wet weather, chickpeas are an excellent long-term lure, because they take a very long time to go moldy.
In rat traps, plain M&M’s are an excellent fit in bait cups, and it’s possible that they would be much harder for slugs and snails to consume than a lure like peanut butter or Nutella. Like mice, rats find it harder to eat M&M’s without being trapped (I wrote a post about M&M’s a while back). There may be a round hard candy that fits in the bait cup as well as plain M&M’s do, but I haven’t managed to find one.
Probably the best potential solution would be to use marbles in your rat traps that have bait cups. I wrote a post about using white marbles that you could search for, if you’d like to. Using white marbles, my T-Rexes and Kness traps have an almost perfect kill record.
By coincidence, I am trapping in Waikanae not far from Nga Manu. Like you I have also found slugs eating my bait and have been actively trying to come up with a solution. Thanks for sharing your collective experience and I will try the chick pea first to see how it works for me.
It might also be worthwhile trying copper tape if the rather neat 3d printed caps don’t work out. Bunnings do a 3" wide strip that ought to work nicely. A strip around either entrance of a tunnel trap should work fine.
Very interesting indeed. Ive tried, marbels, monkey nuts all with very limited results although with monkey nuts disappeared when used as prefeed but were left alone when traps were set. I’m open to anything that will/may improve kill numbers rather than feed slugs etc. Yes I’d appreciate if you would share your stl file…thank you in advance.
Hi Franco,
I’m away from home for a few days but will share the STL file when I return later this week. I can also print off a few and send them out if people are interested in trying them.
Cheers
Rob
With victors I have used pb in small polythene bags tucked under spike in the trigger , odour emits and attracts vermin but slugs/snails can’t devour. Pb lasts forever! Probably wouldn’t work with cup type traps though.
Hi Rob,
Marcus here from traptools.co.nz
I have been wondering about modifying our LureGard to resist slugs, but wasnt sure what size to make the slots. I wonder if you would like to share your file with us so that we could make a change to it?
Cheers
Marcus
Copper tape has been tried but those leopard slugs just plough straight across it. It’s just a minor irritation if any to them but the promise of a feed seems to outweigh any discomfort.
Hi Marcus,
You have probably seen the STL files by now. The holes are around 1mm or so depending on whether a Rat or Mouse trap. There have been concerns about peanut butter clogging the caps. Ideally the trap should not be over filled with pb so the cap is not plugged up. I have an idea for a further improvement by making the grid at the top of the cap hemispherical it may be less likely to clog and be easier to clean.