Prevent wild animals eating them, destroying the border (5)
I believe the answer is:
deter
'prevent' is the definition.
(I've seen this before)
'wild animals eating them destroying the border' is the wordplay.
I cannot quite see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'animals' could be 'deer' (type of animals) and 'deer' is found in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for deter that I've seen before include "Hinder, prevent" , "Discourage (someone from an action)" , "Dishearten" , "Discourage, put off" , "Put off (from an action)" .)