How to get those bad bad wapsies

At Space Camp this summer I caught a glimps of a wasp trap like this, that makes good use of old PET bottles

At home we made two attempts, one out of a half litre bottle and one out of a bigger 1 1/2 litre one. They worked well. I have been told that raw meat is the best bait, but I went for the less smelly option of jam.

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