Neither screws (diameter 3mm, length 20mm) nor spikes (diameter 3mm, length 50mm) stopped the wolves from attacking the dummy. In trials with the screws there were even pieces ripped out of the dummy. Average bites of 0.80 seconds and 1.55 seconds with screws and spikes respectively should be long enough to injure a dog severely. These modifications might give the dog a small time advantage compared to a dog without protection, because the wolves have to adapt to the new situation, but according to these results it cannot protect it from being bitten.

Table: Proportion of trials in which biting occurred