Flipping Timmy broken by possum

We have been using Flipping Timmy s in an area of bush and have found that two out of three times, the possum has broken the yellow sleeve off. One has died a small distance away and the other is nowhere to be seen. Has anyone had this experience and could share any tips on how we can make our device more humane and less likely to break.

Kia ora,
I am a member of the Envirotools team, interested and happy to talk this through.
Please give us a call on this number 045868088 after Easter.
Ngā mihi,