chicks disappear after hatching

I bought Cottage Living a few days ago and have loved playing with it so far. The first day I played it, I hatched a few chickens - no problem. They acted and aged up normally. Yesterday my eggs started disappearing while they were incubating. Today I had 3 eggs hatch - I hatched the chicks with my sim so they definitely hatched and were there. The notification appeared in the corner and everything. But as soon as they hatched, they disappeared. Where did they go? Is this a bug? She has the moodlet for happy bird-day and everything else.