They're not great. They have fairly high water content with not much by way of nutrition and may cause some upset stomach/diarrhea. They're not really harmful in small quantities but a better option would be different kinds of squash as they are more nutritious while still being good sources of hydration.
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!