The slugs are now house trained. 10605 images of slugs have created a fairly good slug detector although there could be improvements by adding blurred images to get the training to focus more on the overall shape of the animals, including their tentacles, or antennae. In deployment, there are quite a few false positives, not really shown on the video below, which was created on a leaf background:

The training shows obvious convergence, even though testing in real life does not pick up on the overall shape of the slugs, but more readily on the patterns on their bodies. Training on AWS Nvidia V100 GPU took about 13 hours to reach 500 epochs:

Training slugs has proved to be more difficult than the common European wasps, probably because the wasps have much more obvious features whereas the slug is more of an amorphous blob with antennae. At this stage, the project is very possibly finished as the limitations of the object detection algorithm has been successfully explored and the conclusion is that more obvious features need to be apparent for effective detection.

Future work would benefit from a better camera eg Logitech Brio 4K rather than Logitech C930e, which would give 4x the pixel density and HDR. Also, more images, possibly another 10,000 of them!