If it is just chewing you are worried about, the solution might be straightforward. There are dedicated products that are normally used to prevent small animals from chewing (and opening) sutures. Commonly applied as a spray, they are non-toxic, but taste massively bitter. I have used that to keep mice from chewing at sutures but also to keep them from gnawing at each other's implanted headplates. Your institute's veterinarian should be able to point you towards the correct product name. 

I agree with Christian. You could try with a chew deterrent for rodents. You could use peppermint essential oil (unpleasant for mice) or bitter tastes (for example Bitter Apple Spray or a quinine solution).

Thanks for your responses! However, it is not just chewing that we are worried about. Social play or aggressive behaviour could make the animals move in such ways that would cause the implant to break off. Therefore, I know that real group-housing is probably not feasible. The goal is really to give them social interaction to some extent, so that they are at least not fully socially isolated.

Thanks for mentioning our article - we do house our rats  in groups on a regular bases. It clearly depends of course on the size of head mount you use.

However, we did try and did not succeed in housing more than two rats together: For whatever reason, with 4 females in one cage, they started hierarchy fights (our interpretation) and we lost some rats (due to implant extraction). Perhaps simple bad luck... we didn't repeat that experiment, though.  

Thank you, that is very useful. Unfortunately, our headstage is a bit bigger than the one described, housing 16 tetrodes. I am afraid we will have to settle for something that allows some contact between animals (e.g. sniffing) without housing them in one area.

What for do you worry?

Isolation depressed rat?

An open wall could avoid it, make soft holes so that they dont catch the headstage.

Richard missed to point out, that our socket was used to hold that type of headstage - although not as a permanent fixture. 

Check out our other paper on that topic

Pinnell, R. C., R. K. Almajidy, R. D. Kirch, J. C. Cassel and U. G. Hofmann (2016). "A Novel, Wireless EEG Recording Method for use Inside the Water Maze " PLOS one 11(2): e0147730.