Over the past 3 weeks, I have learned a very valuable lesson. Back in November of last year, when I ordered 18 baby chicks from a hatchery, I should have paid the additional 20 cents to have them vaccinate the chicks against Marek's Disease. This was probably my third batch of chicks to raise, but my first to order from a hatchery. My first 2 batches came from an older man on the way home from work. I had never heard of Marek's Disease until about 3 weeks ago. Long story short - I had a hen (appr. 4.5 months), start showing strange symptoms out of the blue: wobbly legs, sitting down all the time, and then eventually the wobbly legs turned into "can't walk" legs, and then finally a weird movement of stretching her neck out while opening her mouth. All symptoms pointed to Marek's. I watched youtube videos of other hens with it and the symptoms were all identical to my hen. Long story short - I had to put her down. Well, I had to put another one down yesterday afternoon because she started showing the same symptoms. I had to get her out quickly in hopes of her not infecting the others. Although, I imagine they are all very susceptible to it now anyway. Maybe she will be the last one. NEW CHICK FANATICS - PAY THE EXTRA 20 CENTS FOR THE MAREK'S DISEASE VACCINATION if you are ordering from a hatchery. It may save you some heartache later. Just my amateur advice.