Wahlbergii spontaneous symmetrical antennae shortening?

[Krymz1n]

My adult male P.wahlbergii has lost about 1-2mm of his antennae. They are still even but they are definitely shorter. 

Could he have done this to himself? I can't imagine an accident that would leave both antennae shorter but still the same length. 

Any help at all would be greatly appreciated. He seems content but I'm a little worried about him (he's the leader of the buggy-bunch)

 

[Ranitomeya]

Mantises will chew off damaged/dead parts of their own body. It's possible the tips of his antennae were somehow damaged and he removed them.

 

[Krymz1n]

Something to consider thank you for your expertise