I absolutely agree with the above. An 89g baby in an adult tub feels like a drop of water in the ocean. When my snakes were younger and I was housing them in display enclosures (Animal Plastics T8s), I put in a bunch of crumpled up newspaper in addition to providing multiple hides to help them feel more comfortable. As they grew, I would use less paper until eventually I just had hides for them. Try cluttering the place up and use the above advice about leaving the feeder sit in the enclosure overnight.

Your adults don't use/need hides because the entire tub is basically their hide - they've very different from hatchlings in that regard.