Tunnelling ferrets

Ferrets have a natural love for tunnelling. This is one of the reasons that they are used for hunting rabbits. Unfortunately this love of tunnelling can get them into trouble if the home is not properly 'ferret proofed'. If the ferrets are housed outdoors then care needs to be taken to ensure that the enclosure is completely secure, ferrets can squeeze out into very small spaces when they want to! If your ferret did escape from its outside enclosure and then your garden, it would be very hard to locate it again.
Indoor ferrets that have the run of a particular room or even the entire house can get up to lots of mischief if you are not careful. Ferrets digging a hole in the lining of a sofa and then using the inner compartment as a den is a common problem. We had this problem and tried different tactics including tacking faux leather to the bottom, but alas they are such expert diggers/tunnellers that they managed to get through it in no time! In the end we just cut the bottom from our sofa completely. Unfortunately there are some things you have to sacrifice if you have ferrets as pets.
Gaps behind appliances need to be sealed as well as any exposed holes and wires. My ferrets enjoy rooting through my cupboards so if your low level cupboards do not secure firmly then you may need to invest in safety locks.
To try and satisfy your ferrets' natural urge to tunnel you can buy various toys for them to play with, tunnels being the obvious choice. I have a small cat scratcher house with two holes for them to climb in and out of. They use it as a kind of ferret fort, with one on the inside playfully snapping at the other stuck on the outside. I have a large tunnel toy that has three tunnels that connect in the middle, with a dangle toy in the middle for them to play with. They absolutely love this toy, they play together inside, on their own and also use it as a hiding place. We have a smaller tunnel that they also love, mainly because it has one end closed so one ferret can easily trap the other inside!

Playing peekaboo. 

Playing with the attached toy.

Inside the smaller tunnel.

Please don't forget that your ferret should be supervised while out of the cage, and especially while playing with toys. Also remember to check toys regularly for signs of wear.