I know nothing about snakes but found this one in my house in inland andaluthia Spain,I have an exellent picture of it if anyone would like to email me me at srossington@worldonline.co.uk it is about six inches long and very agressive, searching on the net it could be a ratsnake or or listartes viper possibly,but i'm only guessing really, would be really grateful to know for sure what it is.....Steve.