I don't want to have a lonely tortoise on my hands, so, do they need a friend or two or are they more the solitary types? will they be more active if there is more then one?
Depends on the species and the individual tortoise. What kind do you have? Generally speaking, keeping them together isn't bad, but most don't live in social groups naturally. I wouldn't worry about lonely so much as I would worry about boredom. Make sure their cage is large enough and you may want to try some enrichment tools to get them active and interested in their environment. This website has some ideas on enrichment for captive animals. You may want to try some. Also remember that some may need slight modifications for tortoises depending on size, enclosure, etc. They're just suggestions: http://www.enrichmentonline.org/browse/lis...oises&end=1
Sometimes the males can be aggressive. I've worked with several different groups of torts before without any problems though. It really depends on the species and the individual. It is generally better though to keep individuals housed separately from one another no matter the species, unless breeding. You cut down on the chance of aggression and accidental injury that way.
