Hello, I am a beginner, this is my first year... It is October, the temperatures are in the 50s-60s during the day, and about 30-40 at night. I am in Michigan, it is not that cold yet. I noticed that when the sun comes out and the hive gets warmer, the bees get out and fly, but many fall on the ground at the entrance and it seems they cannot take off again. There are two or three dozens of them on the ground, and this happens regularly. I am worried that gradually the whole hive will just die out because of that. Is this normal? Are they sick? I did do some mite treatment this fall, should I repeat it? Any advice? Thanks in advance!