For the purposes of gaining these still photographs I decided to move the feeding station to one side so that the infrared would not reflect off its plastic surface. I also put down a couple more rubber mats on the patio, as the paving slabs themselves can reflect the infrared from the camera. These results are much better, but as you can see in the above image, the subject of our photo - the hedgehog - is still appearing as a fuzzy white silhouette.
This second photo I'm showing you here is the best of about 40 captures. You can actually make out details of the hedgehog. I think the fact that the hedgehog is to one side of the image is telling. It's not getting the full force of the infrared.
With this in mind I have stuck some more tape over the infrared LEDs on the front of the camera so that its not going to produce such intense and focused light. I've put the camera out again, sprinkled some more mealworms on the rubber mats, and we'll see what results we get in the morning.