I've always heard it was possible to overfeed a VFT and that it could cause death of some or all traps, smaller traps, and slowed or halted growth; I decided to do a small experiment based on these claims out of curiosity.
The short result: Yes, the claims are true.
The long result:
I stopped feeding my VFT for almost three weeks and then stuffed small crickets in 5 of 7 traps on one, and 8 of 10 on the other (I didn't want to utterly kill my VFT's).
- It continued growing while it digested, and over the course of the next week instead of growing faster as would be expected after feeding, it grew slower.
- Two of the new traps are the same size as all the others; one of the traps is about 2/3 the size it should be. These VFT's have never made a "small" trap before.
- One trap died that really should not have. It was a new trap and no part of the insect was sticking out.
- All the traps are open now, and have been for about two weeks while I observed.
- Their growth WAS stunted, pretty badly. The VFT's are no longer growing quickly; they are growing slowly. If I see two flower stalks next week or something I'm going to laugh.
- After two weeks they still have not recovered - they are both growing much more slowly than they used to; no environmental changes (light, water, etc.) were made since before feeding.
I probably would have had different (worse) results if I'd have used bigger food (the crickets were small), or if I'd stuffed all the traps instead of leaving two open; additionally, my fly trap is under very strong lighting and was growing vigorously at the time so it was able to digest faster.
Top left - 3 days before overfeeding (the closed one was triggered by my finger while taking macros)
Top right and bottom left - today