Why do dogs like underwear?

It has been a year ago today that we had to put our beloved 6 year old black lab to sleep. He had lymphoma (labs are more prone to this cancer) and we had to put him to sleep as all his lymph nodes were so swollen he was having difficulty breathing. Buster was such a protector and so mellow. The funniest thing was when he was running full blast around the pool and then slid and fell in! He did not like to swim like most labs do. Poor dog! For Christmas last year I talked my husband into another dog. We went from a 75 lb dog to a 8 lb snowwhite maltese. Our friends, the Nussbaums, own his brother and Todd's mom breeds them. So when we went to there house last december it was hard to resist the tiny little fluffball! Now he is almost a year old and has become the underwear stealer (just ask my mom!) and destroyer. Why do dogs like underwear?! Brandon has now run out of underwear (even though I keep telling the kids if you put your dirty clothes in the hamper Snowball cannot get to them!!) and even I am running low on my mormon undies:) The funniest part about all this is for some reason he decided to chew on the rear of Brandon's favorite plaid shorts. Brandon nor I noticed this and Brandon put them on and was walking around the house the other morning, getting ready for school. Rich asked Brandon "do you realize you have a big hole and your rear is showing?" It really was funny:) Brandon chased the dog all over the house until Snowball hid under my bed (his usual hiding spot and storing spot) where it is hard to get to him. Luckily the hole is on the seam (although it is huge!) so hopefully I can sew them back together. Will be headed to Target later to buy more underwear:)