Also, when we know approximately where you are, it helps us design our answers to better fit your questions.
What kind of tortoise?
What kind of substrate?
What kind of light?
Can you send us a picture of the habitat?
I'm thinking because of your use of the word "mud" that you have the substrate too wet, but I'll need to know the answers to the questions before I say for sure.
People call me tei I live in England and have not even had my tortoises for long I am nearly 14. My enclosure has been atractingany fly my mud is dry the light is at Least 40w and I think ,think that I'm using all purpouse mud .
Oh, I see...you're calling the substrate "mud", but its not really wet mud, just the regular substrate. Ok...
Well, some substrates just seem to attract little flying creatures. Do you know what kind of substrate you have? Is it coconut coir?
I don't think your light is big enough to provide enough heat for your tortoise. What kind of tortoise is it? I use a 100 watt light and it gets the habitat nice and warm for the tortoise.
They are Hermans and are very young. im not sure what type of sub.
But the guy that sold me the torts gave me a booklet to read and it said between 40-60w I haven't had them for that long and I'm only familer with the information provided on the Internet