Do hammers sting each other?

[Mightyfish]

I recently put a smaller hammer right next to a bigger one and their tentacles were touching each other. Within couple of days one side of the smaller hammers have totally withdrawn into its skeleton. Then very quickly the whole body has withdrawn inside skeleton. Now it has disintegrated and died. Do you think it is because it was stung by the bigger hammer or is it because it was a wall hammer and they just died for no reason?

[sabo]

Other reasons. I have 4 all intermingling, two wall, two branched. All happy.

[Webmanny]

Same here. I have two branching next to a frogspawn and they all touch each other all the time and they are all fine.

Here is a shot of them recently.
https://lh5.googleusercontent.com/-VbjxSYWVpr0/VGDADLmYt3I/AAAAAAAAHfY/uzpDaRtX0ok/s800/IMG_20141106_185323.jpg

[Tweaked]

Hammers and frogs are fine. Torches need wide birth from everything.