You're at a friend's house. You have to get home with your bike, but it's dark outside. Think about what you would do in this situation and then click here for some suggestions . See if you thought of these. Prevent bicycle thefts.
Bicycles cost a lot of money.
Get a good lock and chain and carry it with you and use them to lock your bike. Write down the brand name, color, size and serial number. Give these to the police if your bike is stolen. This information will help the police to locate and return your bike to you.