What type of care do they need?
As an adult, or grub?
Adults need fruit like banana, or jellies, along with warmth, light and a cage with objects they can climb on and flip themselves back over.
Grubs- you need a care sheet from your supplier, I have a Goliathus grub, I used coconut substrate and fed it koi pellets with low fat content,
as much as it can eat. The substrate needs cleaned every 48-72 hours, it can be reused. Moisture, damp, not wet, I kept mine on the dry side,
but cool to the touch and it would stick together a bit, but not clump. Maybe that's where I went wrong- see below.
At some point, they stop eating and wander, try to escape at any cost, then you need a pupation material, like clay mixed with peat and sand.
My grub stopped eating early at 35 grams, I gave it the pupation material and it dug in, fairly deep from what I could see, I used a cylinder, like the ones
pepperoni sticks come in.