You are a brand new beekeeper, taken the beekeeping course, bought bees, assembled your equipment, read the books and chose the perfect hive location. You follow the instructions perfectly on how to install a package of bees into a new hive. But to your horror, your bees have left after only a couple days.
Here is the short of it, your new bees didn't like the home you chose for them. You dropped them into their new boxes, gave them sugar syrup and the bees decided it wasn't good enough.
The good news is that you are not alone. Package bees have no reason to stay in a new hive and are often willing to roll the dice and try and build a home somewhere else. Once a queen is released from her cage, the other bees decide if they should stay or go. There is typically a few days the worker bees are in the hive before the queen is released. In that short period, the worker bees are drawing comb using the sugar water given to them for energy. The more drawn comb present in the hive, the more likely a package is to stay put.
It is not that the bees don't like the smell of the wood or that they sensed the sugar water was artificial. Nor is it that they didn't like the foundation or the paint fumes drove them off. The bees don't want to stay because it doesn't smell like a bee hive. The presence of wax, larvae/eggs, a laying queen or brood pheromones (from old comb) will tell the bees this is a good place to start living. But new beekeepers have none of this or little access to it when starting a package.
At this point, you may feel like you are at a loss. Fortunately, you are likely in the middle of prime bee season. You can either buy some more bees (tip: buy a nuc, not a package) or you can try to catch a swarm. You can buy a swarm lure, which can be placed in your now empty hive to lure a swarm. Spring and summer are prime swarm seasons, so the odds of attracting a swarm with a lure are worth betting on.