Your welcome. Lol to totally different ends of the spectrum lol. They are the best. We have a really long wide couch and he has made like 5 laps in and out the pillows and across the back and to each tank on the sides in like 5mins. So yeah lots of movement. Thank you. Oh the only difference between red ackies and yellow is the reds get a little bit bigger and color of course. Check out zoo meds excavator substrate kit too its pretty cool