Same thin happened me a few weeks back on a set that ive never done before it was in the middle of windbushes that were set on fire an its the 1st ive seen the set... Put 2 ferrets in.. 1st ferret wouldnt go in atall and the 2nd ferret came out with a bushy tail(somthing spooked it)... So we got the nets together an the 3 terriers went straight into the hole... 5 mins later a fox bolted out the other side ofthe bank with the terriers right behind lol ferrets are smarter than people think