How much work are they and what do you do when you go on vacation?
Pretty much zero work, go up to the hen house once a day to collect the eggs, while there top off feed and water.
Change straw nesting material about once every two weeks, scrub down and sweep out chicken house about once a month (takes about 2 hours for a 2000 sq ft chicken house.
Use the chicken manure and old straw in garden (rototill in in late fall or very early spring), waste not want not.
If you don’t have a garden just pick a safe place to pile it up, add a little diesel fuel and burn it.
I’m retired now and don’t usually take any vacations but if you still do, just hire a local kid (one you trust) to do the chore list I just gave you.
Pay him/her about 2.50 to 5 dollars a day to take care of the birds, tell the kids mom or dad that all the eggs are free while you are gone (gives them some incentive to make sure the kid stays on the ball).
If your gone for say 14 days that is only 70 dollars if you pay the kid top dollar.
Make sure you critique the kids work when you get back.
You get your birds taken care of, the kid learns how to do a paying job, mom and dad get free eggs, WIN-WIN, whats not to like?