I wouldn't use kong toys as they love rubber & if they happpen to chew off a piece & swallow it it could cause a blockage. Also filling with cream cheese would be bad for them, a couple small licks won't hurt but I wouldn't feed them any more than that.

They love toys of all kinds, mainly cat/baby type toys, toys with bells or rattles or crinckly material. Tunnels to crawl through. blankets. boxes filled with dirt or rice to dig in. If you use rice MAKE SURE it is the RAW LONG GRAIN rice. Instant rice can cause blockages if they swallow pieces.

Ferrets for dummies book is a must have for ferret owners