Fantastic Beasts: The Secrets of Dumbledore (2022)
In the scene where the actor puts his hand into a bucket of grubs, pulls one out, gives it a shake by his ear and eats it, the actor didn’t eat an actual grub. Prior to filming, the grubs were counted out of the holding box, gently brushed off with a soft paintbrush and transferred into a separate box with paper towel in. The grubs were walked to set in the plastic tub.
On action, the grubs were transferred into the bucket just before filming was due to commence. In the bucket was a layer of foam, small amount of substrate and fake silicone grubs. The grubs moved around and started to burrow under the silicone grubs to the substrate.
The grubs were always kept at optimum conditions, which was checked using a laser thermometer. The crew were aware the grubs needed to 10-15 warning to prepare before going on set. This was to ensure they were carefully brushed off with substrate and the boxes were at a suitable temperature.
The handlers were very experienced and counted the grubs in and out of the boxes. They bucket has high walls and so enclosed the grubs so there was no chance of the grubs escaping out of the top.