my terrapins aren't eating as much as b4

[pome422]

hello, anyone got any experience keeping terrapins for a reeeeeeeeally long time? coz i got 2 terrapins (both 15 yrs old) and they aren't eating as much as before. they used to be able to wolf down 6 spoonfuls of terrapin food pellets per feeding but now they only will take 4 spoonfuls with a little leftovers. why is this so? could it be due to stress? or age?

also, they seem to be more lethagic these days. they used to rush to me for food whenever they see me. now they just look at me, stare at me for a while b4 going back to their business. they only rush to me if they see the terrapin food bottle. does this mean that my terrapins are becoming old? or are they being smart (ie they only come to me when they know i have food)?

[pome422]

and just asking: does anyone know how long terrapins live?

[pome422]

any one who knows?